2 * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
3 * Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved.
4 * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved.
5 * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved.
7 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
8 * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
10 * Permission is hereby granted to use or copy this program
11 * for any purpose, provided the above notices are retained on all copies.
12 * Permission to modify the code and to distribute modified code is granted,
13 * provided the above notices are retained, and a notice that the code was
14 * modified is included with the above copyright notice.
19 # include "private/gc_priv.h"
21 # if defined(LINUX) && !defined(POWERPC)
22 # include <linux/version.h>
23 # if (LINUX_VERSION_CODE <= 0x10400)
24 /* Ugly hack to get struct sigcontext_struct definition. Required */
25 /* for some early 1.3.X releases. Will hopefully go away soon. */
26 /* in some later Linux releases, asm/sigcontext.h may have to */
27 /* be included instead. */
29 # include <asm/signal.h>
32 /* Kernels prior to 2.1.1 defined struct sigcontext_struct instead of */
33 /* struct sigcontext. libc6 (glibc2) uses "struct sigcontext" in */
34 /* prototypes, so we have to include the top-level sigcontext.h to */
35 /* make sure the former gets defined to be the latter if appropriate. */
36 # include <features.h>
38 # if 2 == __GLIBC__ && 0 == __GLIBC_MINOR__
39 /* glibc 2.1 no longer has sigcontext.h. But signal.h */
40 /* has the right declaration for glibc 2.1. */
41 # include <sigcontext.h>
42 # endif /* 0 == __GLIBC_MINOR__ */
43 # else /* not 2 <= __GLIBC__ */
44 /* libc5 doesn't have <sigcontext.h>: go directly with the kernel */
45 /* one. Check LINUX_VERSION_CODE to see which we should reference. */
46 # include <asm/sigcontext.h>
47 # endif /* 2 <= __GLIBC__ */
50 # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MACOS) \
52 # include <sys/types.h>
53 # if !defined(MSWIN32) && !defined(SUNOS4)
60 # define SIGSEGV 0 /* value is irrelevant */
65 #if defined(LINUX) || defined(LINUX_STACKBOTTOM)
69 /* Blatantly OS dependent routines, except for those that are related */
70 /* to dynamic loading. */
72 # if defined(HEURISTIC2) || defined(SEARCH_FOR_DATA_START)
73 # define NEED_FIND_LIMIT
76 # if !defined(STACKBOTTOM) && defined(HEURISTIC2)
77 # define NEED_FIND_LIMIT
80 # if (defined(SUNOS4) && defined(DYNAMIC_LOADING)) && !defined(PCR)
81 # define NEED_FIND_LIMIT
84 # if (defined(SVR4) || defined(AUX) || defined(DGUX) \
85 || (defined(LINUX) && defined(SPARC))) && !defined(PCR)
86 # define NEED_FIND_LIMIT
89 #if defined(FREEBSD) && (defined(I386) || defined(powerpc) || defined(__powerpc__))
90 # include <machine/trap.h>
92 # define NEED_FIND_LIMIT
96 #if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__) \
97 && !defined(NEED_FIND_LIMIT)
98 /* Used by GC_init_netbsd_elf() below. */
99 # define NEED_FIND_LIMIT
102 #ifdef NEED_FIND_LIMIT
107 # define GC_AMIGA_DEF
108 # include "AmigaOS.c"
112 #if defined(MSWIN32) || defined(MSWINCE)
113 # define WIN32_LEAN_AND_MEAN
115 # include <windows.h>
119 # include <Processes.h>
123 # include <sys/uio.h>
124 # include <malloc.h> /* for locking */
126 #if defined(USE_MMAP) || defined(USE_MUNMAP)
128 --> USE_MUNMAP requires USE_MMAP
130 # include <sys/types.h>
131 # include <sys/mman.h>
132 # include <sys/stat.h>
138 # if defined(SUNOS5SIGS) && !defined(FREEBSD)
139 # include <sys/siginfo.h>
141 /* Define SETJMP and friends to be the version that restores */
142 /* the signal mask. */
143 # define SETJMP(env) sigsetjmp(env, 1)
144 # define LONGJMP(env, val) siglongjmp(env, val)
145 # define JMP_BUF sigjmp_buf
147 # define SETJMP(env) setjmp(env)
148 # define LONGJMP(env, val) longjmp(env, val)
149 # define JMP_BUF jmp_buf
153 /* for get_etext and friends */
154 #include <mach-o/getsect.h>
158 /* Apparently necessary for djgpp 2.01. May cause problems with */
159 /* other versions. */
160 typedef long unsigned int caddr_t;
164 # include "il/PCR_IL.h"
165 # include "th/PCR_ThCtl.h"
166 # include "mm/PCR_MM.h"
169 #if !defined(NO_EXECUTE_PERMISSION)
170 # define OPT_PROT_EXEC PROT_EXEC
172 # define OPT_PROT_EXEC 0
175 #if defined(LINUX) && \
176 (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64) || !defined(SMALL_CONFIG))
178 /* We need to parse /proc/self/maps, either to find dynamic libraries, */
179 /* and/or to find the register backing store base (IA64). Do it once */
184 /* Repeatedly perform a read call until the buffer is filled or */
185 /* we encounter EOF. */
186 ssize_t GC_repeat_read(int fd, char *buf, size_t count)
188 ssize_t num_read = 0;
191 while (num_read < count) {
192 result = READ(fd, buf + num_read, count - num_read);
193 if (result < 0) return result;
194 if (result == 0) break;
201 * Apply fn to a buffer containing the contents of /proc/self/maps.
202 * Return the result of fn or, if we failed, 0.
203 * We currently do nothing to /proc/self/maps other than simply read
204 * it. This code could be simplified if we could determine its size
208 word GC_apply_to_maps(word (*fn)(char *))
212 size_t maps_size = 4000; /* Initial guess. */
213 static char init_buf[1];
214 static char *maps_buf = init_buf;
215 static size_t maps_buf_sz = 1;
217 /* Read /proc/self/maps, growing maps_buf as necessary. */
218 /* Note that we may not allocate conventionally, and */
219 /* thus can't use stdio. */
221 if (maps_size >= maps_buf_sz) {
222 /* Grow only by powers of 2, since we leak "too small" buffers. */
223 while (maps_size >= maps_buf_sz) maps_buf_sz *= 2;
224 maps_buf = GC_scratch_alloc(maps_buf_sz);
225 if (maps_buf == 0) return 0;
227 f = open("/proc/self/maps", O_RDONLY);
228 if (-1 == f) return 0;
231 result = GC_repeat_read(f, maps_buf, maps_buf_sz-1);
232 if (result <= 0) return 0;
234 } while (result == maps_buf_sz-1);
236 } while (maps_size >= maps_buf_sz);
237 maps_buf[maps_size] = '\0';
239 /* Apply fn to result. */
243 #endif /* Need GC_apply_to_maps */
245 #if defined(LINUX) && (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64))
247 // GC_parse_map_entry parses an entry from /proc/self/maps so we can
248 // locate all writable data segments that belong to shared libraries.
249 // The format of one of these entries and the fields we care about
251 // XXXXXXXX-XXXXXXXX r-xp 00000000 30:05 260537 name of mapping...\n
252 // ^^^^^^^^ ^^^^^^^^ ^^^^ ^^
253 // start end prot maj_dev
255 // Note that since about auguat 2003 kernels, the columns no longer have
256 // fixed offsets on 64-bit kernels. Hence we no longer rely on fixed offsets
257 // anywhere, which is safer anyway.
261 * Assign various fields of the first line in buf_ptr to *start, *end,
262 * *prot_buf and *maj_dev. Only *prot_buf may be set for unwritable maps.
264 char *GC_parse_map_entry(char *buf_ptr, word *start, word *end,
265 char *prot_buf, unsigned int *maj_dev)
267 char *start_start, *end_start, *prot_start, *maj_dev_start;
271 if (buf_ptr == NULL || *buf_ptr == '\0') {
276 while (isspace(*p)) ++p;
278 GC_ASSERT(isxdigit(*start_start));
279 *start = strtoul(start_start, &endp, 16); p = endp;
284 GC_ASSERT(isxdigit(*end_start));
285 *end = strtoul(end_start, &endp, 16); p = endp;
286 GC_ASSERT(isspace(*p));
288 while (isspace(*p)) ++p;
290 GC_ASSERT(*prot_start == 'r' || *prot_start == '-');
291 memcpy(prot_buf, prot_start, 4);
293 if (prot_buf[1] == 'w') {/* we can skip the rest if it's not writable. */
294 /* Skip past protection field to offset field */
295 while (!isspace(*p)) ++p; while (isspace(*p)) ++p;
296 GC_ASSERT(isxdigit(*p));
297 /* Skip past offset field, which we ignore */
298 while (!isspace(*p)) ++p; while (isspace(*p)) ++p;
300 GC_ASSERT(isxdigit(*maj_dev_start));
301 *maj_dev = strtoul(maj_dev_start, NULL, 16);
304 while (*p && *p++ != '\n');
309 #endif /* Need to parse /proc/self/maps. */
311 #if defined(SEARCH_FOR_DATA_START)
312 /* The I386 case can be handled without a search. The Alpha case */
313 /* used to be handled differently as well, but the rules changed */
314 /* for recent Linux versions. This seems to be the easiest way to */
315 /* cover all versions. */
318 /* Some Linux distributions arrange to define __data_start. Some */
319 /* define data_start as a weak symbol. The latter is technically */
320 /* broken, since the user program may define data_start, in which */
321 /* case we lose. Nonetheless, we try both, prefering __data_start. */
322 /* We assume gcc-compatible pragmas. */
323 # pragma weak __data_start
324 extern int __data_start[];
325 # pragma weak data_start
326 extern int data_start[];
332 void GC_init_linux_data_start()
334 extern ptr_t GC_find_limit();
337 /* Try the easy approaches first: */
338 if ((ptr_t)__data_start != 0) {
339 GC_data_start = (ptr_t)(__data_start);
342 if ((ptr_t)data_start != 0) {
343 GC_data_start = (ptr_t)(data_start);
347 GC_data_start = GC_find_limit((ptr_t)(_end), FALSE);
353 # ifndef ECOS_GC_MEMORY_SIZE
354 # define ECOS_GC_MEMORY_SIZE (448 * 1024)
355 # endif /* ECOS_GC_MEMORY_SIZE */
357 // setjmp() function, as described in ANSI para 7.6.1.1
359 #define SETJMP( __env__ ) hal_setjmp( __env__ )
361 // FIXME: This is a simple way of allocating memory which is
362 // compatible with ECOS early releases. Later releases use a more
363 // sophisticated means of allocating memory than this simple static
364 // allocator, but this method is at least bound to work.
365 static char memory[ECOS_GC_MEMORY_SIZE];
366 static char *brk = memory;
368 static void *tiny_sbrk(ptrdiff_t increment)
374 if (brk > memory + sizeof memory)
382 #define sbrk tiny_sbrk
385 #if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__)
388 void GC_init_netbsd_elf()
390 extern ptr_t GC_find_limit();
391 extern char **environ;
392 /* This may need to be environ, without the underscore, for */
394 GC_data_start = GC_find_limit((ptr_t)&environ, FALSE);
402 # if !defined(__IBMC__) && !defined(__WATCOMC__) /* e.g. EMX */
405 unsigned short magic_number;
406 unsigned short padding[29];
410 #define E_MAGIC(x) (x).magic_number
411 #define EMAGIC 0x5A4D
412 #define E_LFANEW(x) (x).new_exe_offset
415 unsigned char magic_number[2];
416 unsigned char byte_order;
417 unsigned char word_order;
418 unsigned long exe_format_level;
421 unsigned long padding1[13];
422 unsigned long object_table_offset;
423 unsigned long object_count;
424 unsigned long padding2[31];
427 #define E32_MAGIC1(x) (x).magic_number[0]
428 #define E32MAGIC1 'L'
429 #define E32_MAGIC2(x) (x).magic_number[1]
430 #define E32MAGIC2 'X'
431 #define E32_BORDER(x) (x).byte_order
433 #define E32_WORDER(x) (x).word_order
435 #define E32_CPU(x) (x).cpu
437 #define E32_OBJTAB(x) (x).object_table_offset
438 #define E32_OBJCNT(x) (x).object_count
444 unsigned long pagemap;
445 unsigned long mapsize;
446 unsigned long reserved;
449 #define O32_FLAGS(x) (x).flags
450 #define OBJREAD 0x0001L
451 #define OBJWRITE 0x0002L
452 #define OBJINVALID 0x0080L
453 #define O32_SIZE(x) (x).size
454 #define O32_BASE(x) (x).base
456 # else /* IBM's compiler */
458 /* A kludge to get around what appears to be a header file bug */
460 # define WORD unsigned short
463 # define DWORD unsigned long
470 # endif /* __IBMC__ */
472 # define INCL_DOSEXCEPTIONS
473 # define INCL_DOSPROCESS
474 # define INCL_DOSERRORS
475 # define INCL_DOSMODULEMGR
476 # define INCL_DOSMEMMGR
480 /* Disable and enable signals during nontrivial allocations */
482 void GC_disable_signals(void)
486 DosEnterMustComplete(&nest);
487 if (nest != 1) ABORT("nested GC_disable_signals");
490 void GC_enable_signals(void)
494 DosExitMustComplete(&nest);
495 if (nest != 0) ABORT("GC_enable_signals");
501 # if !defined(PCR) && !defined(AMIGA) && !defined(MSWIN32) \
502 && !defined(MSWINCE) \
503 && !defined(MACOS) && !defined(DJGPP) && !defined(DOS4GW) \
504 && !defined(NOSYS) && !defined(ECOS)
506 # if defined(sigmask) && !defined(UTS4) && !defined(HURD)
507 /* Use the traditional BSD interface */
508 # define SIGSET_T int
509 # define SIG_DEL(set, signal) (set) &= ~(sigmask(signal))
510 # define SIG_FILL(set) (set) = 0x7fffffff
511 /* Setting the leading bit appears to provoke a bug in some */
512 /* longjmp implementations. Most systems appear not to have */
514 # define SIGSETMASK(old, new) (old) = sigsetmask(new)
516 /* Use POSIX/SYSV interface */
517 # define SIGSET_T sigset_t
518 # define SIG_DEL(set, signal) sigdelset(&(set), (signal))
519 # define SIG_FILL(set) sigfillset(&set)
520 # define SIGSETMASK(old, new) sigprocmask(SIG_SETMASK, &(new), &(old))
523 static GC_bool mask_initialized = FALSE;
525 static SIGSET_T new_mask;
527 static SIGSET_T old_mask;
529 static SIGSET_T dummy;
531 #if defined(PRINTSTATS) && !defined(THREADS)
532 # define CHECK_SIGNALS
533 int GC_sig_disabled = 0;
536 void GC_disable_signals()
538 if (!mask_initialized) {
541 SIG_DEL(new_mask, SIGSEGV);
542 SIG_DEL(new_mask, SIGILL);
543 SIG_DEL(new_mask, SIGQUIT);
545 SIG_DEL(new_mask, SIGBUS);
548 SIG_DEL(new_mask, SIGIOT);
551 SIG_DEL(new_mask, SIGEMT);
554 SIG_DEL(new_mask, SIGTRAP);
556 mask_initialized = TRUE;
558 # ifdef CHECK_SIGNALS
559 if (GC_sig_disabled != 0) ABORT("Nested disables");
562 SIGSETMASK(old_mask,new_mask);
565 void GC_enable_signals()
567 # ifdef CHECK_SIGNALS
568 if (GC_sig_disabled != 1) ABORT("Unmatched enable");
571 SIGSETMASK(dummy,old_mask);
578 /* Ivan Demakov: simplest way (to me) */
580 void GC_disable_signals() { }
581 void GC_enable_signals() { }
584 /* Find the page size */
587 # if defined(MSWIN32) || defined(MSWINCE)
588 void GC_setpagesize()
590 GetSystemInfo(&GC_sysinfo);
591 GC_page_size = GC_sysinfo.dwPageSize;
595 # if defined(MPROTECT_VDB) || defined(PROC_VDB) || defined(USE_MMAP) \
596 || defined(USE_MUNMAP)
597 void GC_setpagesize()
599 GC_page_size = GETPAGESIZE();
602 /* It's acceptable to fake it. */
603 void GC_setpagesize()
605 GC_page_size = HBLKSIZE;
611 * Find the base of the stack.
612 * Used only in single-threaded environment.
613 * With threads, GC_mark_roots needs to know how to do this.
614 * Called with allocator lock held.
616 # if defined(MSWIN32) || defined(MSWINCE)
617 # define is_writable(prot) ((prot) == PAGE_READWRITE \
618 || (prot) == PAGE_WRITECOPY \
619 || (prot) == PAGE_EXECUTE_READWRITE \
620 || (prot) == PAGE_EXECUTE_WRITECOPY)
621 /* Return the number of bytes that are writable starting at p. */
622 /* The pointer p is assumed to be page aligned. */
623 /* If base is not 0, *base becomes the beginning of the */
624 /* allocation region containing p. */
625 word GC_get_writable_length(ptr_t p, ptr_t *base)
627 MEMORY_BASIC_INFORMATION buf;
631 result = VirtualQuery(p, &buf, sizeof(buf));
632 if (result != sizeof(buf)) ABORT("Weird VirtualQuery result");
633 if (base != 0) *base = (ptr_t)(buf.AllocationBase);
634 protect = (buf.Protect & ~(PAGE_GUARD | PAGE_NOCACHE));
635 if (!is_writable(protect)) {
638 if (buf.State != MEM_COMMIT) return(0);
639 return(buf.RegionSize);
642 ptr_t GC_get_stack_base()
645 ptr_t sp = (ptr_t)(&dummy);
646 ptr_t trunc_sp = (ptr_t)((word)sp & ~(GC_page_size - 1));
647 word size = GC_get_writable_length(trunc_sp, 0);
649 return(trunc_sp + size);
653 # endif /* MS Windows */
656 # include <kernel/OS.h>
657 ptr_t GC_get_stack_base(){
659 get_thread_info(find_thread(NULL),&th);
667 ptr_t GC_get_stack_base()
672 if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
673 GC_err_printf0("DosGetInfoBlocks failed\n");
674 ABORT("DosGetInfoBlocks failed\n");
676 return((ptr_t)(ptib -> tib_pstacklimit));
683 # include "AmigaOS.c"
687 # if defined(NEED_FIND_LIMIT) || defined(UNIX_LIKE)
690 typedef void (*handler)(int);
692 typedef void (*handler)();
695 # if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) \
696 || defined(HURD) || defined(NETBSD)
697 static struct sigaction old_segv_act;
698 # if defined(IRIX5) || defined(HPUX) \
699 || defined(HURD) || defined(NETBSD)
700 static struct sigaction old_bus_act;
703 static handler old_segv_handler, old_bus_handler;
707 void GC_set_and_save_fault_handler(handler h)
709 void GC_set_and_save_fault_handler(h)
713 # if defined(SUNOS5SIGS) || defined(IRIX5) \
714 || defined(OSF1) || defined(HURD) || defined(NETBSD)
715 struct sigaction act;
718 # if 0 /* Was necessary for Solaris 2.3 and very temporary */
720 act.sa_flags = SA_RESTART | SA_NODEFER;
722 act.sa_flags = SA_RESTART;
725 (void) sigemptyset(&act.sa_mask);
726 # ifdef GC_IRIX_THREADS
727 /* Older versions have a bug related to retrieving and */
728 /* and setting a handler at the same time. */
729 (void) sigaction(SIGSEGV, 0, &old_segv_act);
730 (void) sigaction(SIGSEGV, &act, 0);
731 (void) sigaction(SIGBUS, 0, &old_bus_act);
732 (void) sigaction(SIGBUS, &act, 0);
734 (void) sigaction(SIGSEGV, &act, &old_segv_act);
735 # if defined(IRIX5) \
736 || defined(HPUX) || defined(HURD) || defined(NETBSD)
737 /* Under Irix 5.x or HP/UX, we may get SIGBUS. */
738 /* Pthreads doesn't exist under Irix 5.x, so we */
739 /* don't have to worry in the threads case. */
740 (void) sigaction(SIGBUS, &act, &old_bus_act);
742 # endif /* GC_IRIX_THREADS */
744 old_segv_handler = signal(SIGSEGV, h);
746 old_bus_handler = signal(SIGBUS, h);
750 # endif /* NEED_FIND_LIMIT || UNIX_LIKE */
752 # ifdef NEED_FIND_LIMIT
753 /* Some tools to implement HEURISTIC2 */
754 # define MIN_PAGE_SIZE 256 /* Smallest conceivable page size, bytes */
755 /* static */ JMP_BUF GC_jmp_buf;
758 void GC_fault_handler(sig)
761 LONGJMP(GC_jmp_buf, 1);
764 void GC_setup_temporary_fault_handler()
766 GC_set_and_save_fault_handler(GC_fault_handler);
769 void GC_reset_fault_handler()
771 # if defined(SUNOS5SIGS) || defined(IRIX5) \
772 || defined(OSF1) || defined(HURD) || defined(NETBSD)
773 (void) sigaction(SIGSEGV, &old_segv_act, 0);
774 # if defined(IRIX5) \
775 || defined(HPUX) || defined(HURD) || defined(NETBSD)
776 (void) sigaction(SIGBUS, &old_bus_act, 0);
779 (void) signal(SIGSEGV, old_segv_handler);
781 (void) signal(SIGBUS, old_bus_handler);
786 /* Return the first nonaddressible location > p (up) or */
787 /* the smallest location q s.t. [q,p) is addressable (!up). */
788 /* We assume that p (up) or p-1 (!up) is addressable. */
789 ptr_t GC_find_limit(p, up)
793 static VOLATILE ptr_t result;
794 /* Needs to be static, since otherwise it may not be */
795 /* preserved across the longjmp. Can safely be */
796 /* static since it's only called once, with the */
797 /* allocation lock held. */
800 GC_setup_temporary_fault_handler();
801 if (SETJMP(GC_jmp_buf) == 0) {
802 result = (ptr_t)(((word)(p))
803 & ~(MIN_PAGE_SIZE-1));
806 result += MIN_PAGE_SIZE;
808 result -= MIN_PAGE_SIZE;
810 GC_noop1((word)(*result));
813 GC_reset_fault_handler();
815 result += MIN_PAGE_SIZE;
821 #if defined(ECOS) || defined(NOSYS)
822 ptr_t GC_get_stack_base()
828 #ifdef HPUX_STACKBOTTOM
830 #include <sys/param.h>
831 #include <sys/pstat.h>
833 ptr_t GC_get_register_stack_base(void)
835 struct pst_vm_status vm_status;
838 while (pstat_getprocvm(&vm_status, sizeof(vm_status), 0, i++) == 1) {
839 if (vm_status.pst_type == PS_RSESTACK) {
840 return (ptr_t) vm_status.pst_vaddr;
844 /* old way to get the register stackbottom */
845 return (ptr_t)(((word)GC_stackbottom - BACKING_STORE_DISPLACEMENT - 1)
846 & ~(BACKING_STORE_ALIGNMENT - 1));
849 #endif /* HPUX_STACK_BOTTOM */
851 #ifdef LINUX_STACKBOTTOM
853 #include <sys/types.h>
854 #include <sys/stat.h>
856 # define STAT_SKIP 27 /* Number of fields preceding startstack */
857 /* field in /proc/self/stat */
859 #ifdef USE_LIBC_PRIVATES
860 # pragma weak __libc_stack_end
861 extern ptr_t __libc_stack_end;
865 /* Try to read the backing store base from /proc/self/maps. */
866 /* We look for the writable mapping with a 0 major device, */
867 /* which is as close to our frame as possible, but below it.*/
868 static word backing_store_base_from_maps(char *maps)
871 char *buf_ptr = maps;
873 unsigned int maj_dev;
874 word current_best = 0;
878 buf_ptr = GC_parse_map_entry(buf_ptr, &start, &end, prot_buf, &maj_dev);
879 if (buf_ptr == NULL) return current_best;
880 if (prot_buf[1] == 'w' && maj_dev == 0) {
881 if (end < (word)(&dummy) && start > current_best) current_best = start;
887 static word backing_store_base_from_proc(void)
889 return GC_apply_to_maps(backing_store_base_from_maps);
892 # ifdef USE_LIBC_PRIVATES
893 # pragma weak __libc_ia64_register_backing_store_base
894 extern ptr_t __libc_ia64_register_backing_store_base;
897 ptr_t GC_get_register_stack_base(void)
899 # ifdef USE_LIBC_PRIVATES
900 if (0 != &__libc_ia64_register_backing_store_base
901 && 0 != __libc_ia64_register_backing_store_base) {
902 /* Glibc 2.2.4 has a bug such that for dynamically linked */
903 /* executables __libc_ia64_register_backing_store_base is */
904 /* defined but uninitialized during constructor calls. */
905 /* Hence we check for both nonzero address and value. */
906 return __libc_ia64_register_backing_store_base;
909 word result = backing_store_base_from_proc();
911 /* Use dumb heuristics. Works only for default configuration. */
912 result = (word)GC_stackbottom - BACKING_STORE_DISPLACEMENT;
913 result += BACKING_STORE_ALIGNMENT - 1;
914 result &= ~(BACKING_STORE_ALIGNMENT - 1);
915 /* Verify that it's at least readable. If not, we goofed. */
916 GC_noop1(*(word *)result);
918 return (ptr_t)result;
922 ptr_t GC_linux_stack_base(void)
924 /* We read the stack base value from /proc/self/stat. We do this */
925 /* using direct I/O system calls in order to avoid calling malloc */
926 /* in case REDIRECT_MALLOC is defined. */
927 # define STAT_BUF_SIZE 4096
928 # define STAT_READ read
929 /* Should probably call the real read, if read is wrapped. */
930 char stat_buf[STAT_BUF_SIZE];
934 size_t i, buf_offset = 0;
936 /* First try the easy way. This should work for glibc 2.2 */
937 /* This fails in a prelinked ("prelink" command) executable */
938 /* since the correct value of __libc_stack_end never */
939 /* becomes visible to us. The second test works around */
941 # ifdef USE_LIBC_PRIVATES
942 if (0 != &__libc_stack_end && 0 != __libc_stack_end ) {
944 /* Some versions of glibc set the address 16 bytes too */
945 /* low while the initialization code is running. */
946 if (((word)__libc_stack_end & 0xfff) + 0x10 < 0x1000) {
947 return __libc_stack_end + 0x10;
948 } /* Otherwise it's not safe to add 16 bytes and we fall */
949 /* back to using /proc. */
952 /* Older versions of glibc for 64-bit Sparc do not set
953 * this variable correctly, it gets set to either zero
956 if (__libc_stack_end != (ptr_t) (unsigned long)0x1)
957 return __libc_stack_end;
959 return __libc_stack_end;
964 f = open("/proc/self/stat", O_RDONLY);
965 if (f < 0 || STAT_READ(f, stat_buf, STAT_BUF_SIZE) < 2 * STAT_SKIP) {
966 ABORT("Couldn't read /proc/self/stat");
968 c = stat_buf[buf_offset++];
969 /* Skip the required number of fields. This number is hopefully */
970 /* constant across all Linux implementations. */
971 for (i = 0; i < STAT_SKIP; ++i) {
972 while (isspace(c)) c = stat_buf[buf_offset++];
973 while (!isspace(c)) c = stat_buf[buf_offset++];
975 while (isspace(c)) c = stat_buf[buf_offset++];
979 c = stat_buf[buf_offset++];
982 if (result < 0x10000000) ABORT("Absurd stack bottom value");
983 return (ptr_t)result;
986 #endif /* LINUX_STACKBOTTOM */
988 #ifdef FREEBSD_STACKBOTTOM
990 /* This uses an undocumented sysctl call, but at least one expert */
991 /* believes it will stay. */
994 #include <sys/types.h>
995 #include <sys/sysctl.h>
997 ptr_t GC_freebsd_stack_base(void)
999 int nm[2] = {CTL_KERN, KERN_USRSTACK};
1001 size_t len = sizeof(ptr_t);
1002 int r = sysctl(nm, 2, &base, &len, NULL, 0);
1004 if (r) ABORT("Error getting stack base");
1009 #endif /* FREEBSD_STACKBOTTOM */
1011 #if !defined(BEOS) && !defined(AMIGA) && !defined(MSWIN32) \
1012 && !defined(MSWINCE) && !defined(OS2) && !defined(NOSYS) && !defined(ECOS)
1014 ptr_t GC_get_stack_base()
1016 # if defined(HEURISTIC1) || defined(HEURISTIC2) || \
1017 defined(LINUX_STACKBOTTOM) || defined(FREEBSD_STACKBOTTOM)
1022 # define STACKBOTTOM_ALIGNMENT_M1 ((word)STACK_GRAN - 1)
1025 return(STACKBOTTOM);
1028 # ifdef STACK_GROWS_DOWN
1029 result = (ptr_t)((((word)(&dummy))
1030 + STACKBOTTOM_ALIGNMENT_M1)
1031 & ~STACKBOTTOM_ALIGNMENT_M1);
1033 result = (ptr_t)(((word)(&dummy))
1034 & ~STACKBOTTOM_ALIGNMENT_M1);
1036 # endif /* HEURISTIC1 */
1037 # ifdef LINUX_STACKBOTTOM
1038 result = GC_linux_stack_base();
1040 # ifdef FREEBSD_STACKBOTTOM
1041 result = GC_freebsd_stack_base();
1044 # ifdef STACK_GROWS_DOWN
1045 result = GC_find_limit((ptr_t)(&dummy), TRUE);
1046 # ifdef HEURISTIC2_LIMIT
1047 if (result > HEURISTIC2_LIMIT
1048 && (ptr_t)(&dummy) < HEURISTIC2_LIMIT) {
1049 result = HEURISTIC2_LIMIT;
1053 result = GC_find_limit((ptr_t)(&dummy), FALSE);
1054 # ifdef HEURISTIC2_LIMIT
1055 if (result < HEURISTIC2_LIMIT
1056 && (ptr_t)(&dummy) > HEURISTIC2_LIMIT) {
1057 result = HEURISTIC2_LIMIT;
1062 # endif /* HEURISTIC2 */
1063 # ifdef STACK_GROWS_DOWN
1064 if (result == 0) result = (ptr_t)(signed_word)(-sizeof(ptr_t));
1067 # endif /* STACKBOTTOM */
1070 # endif /* ! AMIGA, !OS 2, ! MS Windows, !BEOS, !NOSYS, !ECOS */
1073 * Register static data segment(s) as roots.
1074 * If more data segments are added later then they need to be registered
1075 * add that point (as we do with SunOS dynamic loading),
1076 * or GC_mark_roots needs to check for them (as we do with PCR).
1077 * Called with allocator lock held.
1082 void GC_register_data_segments()
1086 HMODULE module_handle;
1087 # define PBUFSIZ 512
1088 UCHAR path[PBUFSIZ];
1090 struct exe_hdr hdrdos; /* MSDOS header. */
1091 struct e32_exe hdr386; /* Real header for my executable */
1092 struct o32_obj seg; /* Currrent segment */
1096 if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
1097 GC_err_printf0("DosGetInfoBlocks failed\n");
1098 ABORT("DosGetInfoBlocks failed\n");
1100 module_handle = ppib -> pib_hmte;
1101 if (DosQueryModuleName(module_handle, PBUFSIZ, path) != NO_ERROR) {
1102 GC_err_printf0("DosQueryModuleName failed\n");
1103 ABORT("DosGetInfoBlocks failed\n");
1105 myexefile = fopen(path, "rb");
1106 if (myexefile == 0) {
1107 GC_err_puts("Couldn't open executable ");
1108 GC_err_puts(path); GC_err_puts("\n");
1109 ABORT("Failed to open executable\n");
1111 if (fread((char *)(&hdrdos), 1, sizeof hdrdos, myexefile) < sizeof hdrdos) {
1112 GC_err_puts("Couldn't read MSDOS header from ");
1113 GC_err_puts(path); GC_err_puts("\n");
1114 ABORT("Couldn't read MSDOS header");
1116 if (E_MAGIC(hdrdos) != EMAGIC) {
1117 GC_err_puts("Executable has wrong DOS magic number: ");
1118 GC_err_puts(path); GC_err_puts("\n");
1119 ABORT("Bad DOS magic number");
1121 if (fseek(myexefile, E_LFANEW(hdrdos), SEEK_SET) != 0) {
1122 GC_err_puts("Seek to new header failed in ");
1123 GC_err_puts(path); GC_err_puts("\n");
1124 ABORT("Bad DOS magic number");
1126 if (fread((char *)(&hdr386), 1, sizeof hdr386, myexefile) < sizeof hdr386) {
1127 GC_err_puts("Couldn't read MSDOS header from ");
1128 GC_err_puts(path); GC_err_puts("\n");
1129 ABORT("Couldn't read OS/2 header");
1131 if (E32_MAGIC1(hdr386) != E32MAGIC1 || E32_MAGIC2(hdr386) != E32MAGIC2) {
1132 GC_err_puts("Executable has wrong OS/2 magic number:");
1133 GC_err_puts(path); GC_err_puts("\n");
1134 ABORT("Bad OS/2 magic number");
1136 if ( E32_BORDER(hdr386) != E32LEBO || E32_WORDER(hdr386) != E32LEWO) {
1137 GC_err_puts("Executable %s has wrong byte order: ");
1138 GC_err_puts(path); GC_err_puts("\n");
1139 ABORT("Bad byte order");
1141 if ( E32_CPU(hdr386) == E32CPU286) {
1142 GC_err_puts("GC can't handle 80286 executables: ");
1143 GC_err_puts(path); GC_err_puts("\n");
1146 if (fseek(myexefile, E_LFANEW(hdrdos) + E32_OBJTAB(hdr386),
1148 GC_err_puts("Seek to object table failed: ");
1149 GC_err_puts(path); GC_err_puts("\n");
1150 ABORT("Seek to object table failed");
1152 for (nsegs = E32_OBJCNT(hdr386); nsegs > 0; nsegs--) {
1154 if (fread((char *)(&seg), 1, sizeof seg, myexefile) < sizeof seg) {
1155 GC_err_puts("Couldn't read obj table entry from ");
1156 GC_err_puts(path); GC_err_puts("\n");
1157 ABORT("Couldn't read obj table entry");
1159 flags = O32_FLAGS(seg);
1160 if (!(flags & OBJWRITE)) continue;
1161 if (!(flags & OBJREAD)) continue;
1162 if (flags & OBJINVALID) {
1163 GC_err_printf0("Object with invalid pages?\n");
1166 GC_add_roots_inner(O32_BASE(seg), O32_BASE(seg)+O32_SIZE(seg), FALSE);
1172 # if defined(MSWIN32) || defined(MSWINCE)
1175 /* Unfortunately, we have to handle win32s very differently from NT, */
1176 /* Since VirtualQuery has very different semantics. In particular, */
1177 /* under win32s a VirtualQuery call on an unmapped page returns an */
1178 /* invalid result. Under NT, GC_register_data_segments is a noop and */
1179 /* all real work is done by GC_register_dynamic_libraries. Under */
1180 /* win32s, we cannot find the data segments associated with dll's. */
1181 /* We register the main data segment here. */
1182 GC_bool GC_no_win32_dlls = FALSE;
1183 /* This used to be set for gcc, to avoid dealing with */
1184 /* the structured exception handling issues. But we now have */
1185 /* assembly code to do that right. */
1187 void GC_init_win32()
1189 /* if we're running under win32s, assume that no DLLs will be loaded */
1190 DWORD v = GetVersion();
1191 GC_no_win32_dlls |= ((v & 0x80000000) && (v & 0xff) <= 3);
1194 /* Return the smallest address a such that VirtualQuery */
1195 /* returns correct results for all addresses between a and start. */
1196 /* Assumes VirtualQuery returns correct information for start. */
1197 ptr_t GC_least_described_address(ptr_t start)
1199 MEMORY_BASIC_INFORMATION buf;
1205 limit = GC_sysinfo.lpMinimumApplicationAddress;
1206 p = (ptr_t)((word)start & ~(GC_page_size - 1));
1208 q = (LPVOID)(p - GC_page_size);
1209 if ((ptr_t)q > (ptr_t)p /* underflow */ || q < limit) break;
1210 result = VirtualQuery(q, &buf, sizeof(buf));
1211 if (result != sizeof(buf) || buf.AllocationBase == 0) break;
1212 p = (ptr_t)(buf.AllocationBase);
1218 # ifndef REDIRECT_MALLOC
1219 /* We maintain a linked list of AllocationBase values that we know */
1220 /* correspond to malloc heap sections. Currently this is only called */
1221 /* during a GC. But there is some hope that for long running */
1222 /* programs we will eventually see most heap sections. */
1224 /* In the long run, it would be more reliable to occasionally walk */
1225 /* the malloc heap with HeapWalk on the default heap. But that */
1226 /* apparently works only for NT-based Windows. */
1228 /* In the long run, a better data structure would also be nice ... */
1229 struct GC_malloc_heap_list {
1230 void * allocation_base;
1231 struct GC_malloc_heap_list *next;
1232 } *GC_malloc_heap_l = 0;
1234 /* Is p the base of one of the malloc heap sections we already know */
1236 GC_bool GC_is_malloc_heap_base(ptr_t p)
1238 struct GC_malloc_heap_list *q = GC_malloc_heap_l;
1241 if (q -> allocation_base == p) return TRUE;
1247 void *GC_get_allocation_base(void *p)
1249 MEMORY_BASIC_INFORMATION buf;
1250 DWORD result = VirtualQuery(p, &buf, sizeof(buf));
1251 if (result != sizeof(buf)) {
1252 ABORT("Weird VirtualQuery result");
1254 return buf.AllocationBase;
1257 size_t GC_max_root_size = 100000; /* Appr. largest root size. */
1259 void GC_add_current_malloc_heap()
1261 struct GC_malloc_heap_list *new_l =
1262 malloc(sizeof(struct GC_malloc_heap_list));
1263 void * candidate = GC_get_allocation_base(new_l);
1265 if (new_l == 0) return;
1266 if (GC_is_malloc_heap_base(candidate)) {
1267 /* Try a little harder to find malloc heap. */
1268 size_t req_size = 10000;
1270 void *p = malloc(req_size);
1271 if (0 == p) { free(new_l); return; }
1272 candidate = GC_get_allocation_base(p);
1275 } while (GC_is_malloc_heap_base(candidate)
1276 && req_size < GC_max_root_size/10 && req_size < 500000);
1277 if (GC_is_malloc_heap_base(candidate)) {
1278 free(new_l); return;
1283 GC_printf1("Found new system malloc AllocationBase at 0x%lx\n",
1286 new_l -> allocation_base = candidate;
1287 new_l -> next = GC_malloc_heap_l;
1288 GC_malloc_heap_l = new_l;
1290 # endif /* REDIRECT_MALLOC */
1292 /* Is p the start of either the malloc heap, or of one of our */
1293 /* heap sections? */
1294 GC_bool GC_is_heap_base (ptr_t p)
1299 # ifndef REDIRECT_MALLOC
1300 static word last_gc_no = -1;
1302 if (last_gc_no != GC_gc_no) {
1303 GC_add_current_malloc_heap();
1304 last_gc_no = GC_gc_no;
1306 if (GC_root_size > GC_max_root_size) GC_max_root_size = GC_root_size;
1307 if (GC_is_malloc_heap_base(p)) return TRUE;
1309 for (i = 0; i < GC_n_heap_bases; i++) {
1310 if (GC_heap_bases[i] == p) return TRUE;
1316 void GC_register_root_section(ptr_t static_root)
1318 MEMORY_BASIC_INFORMATION buf;
1323 char * limit, * new_limit;
1325 if (!GC_no_win32_dlls) return;
1326 p = base = limit = GC_least_described_address(static_root);
1327 while (p < GC_sysinfo.lpMaximumApplicationAddress) {
1328 result = VirtualQuery(p, &buf, sizeof(buf));
1329 if (result != sizeof(buf) || buf.AllocationBase == 0
1330 || GC_is_heap_base(buf.AllocationBase)) break;
1331 new_limit = (char *)p + buf.RegionSize;
1332 protect = buf.Protect;
1333 if (buf.State == MEM_COMMIT
1334 && is_writable(protect)) {
1335 if ((char *)p == limit) {
1338 if (base != limit) GC_add_roots_inner(base, limit, FALSE);
1343 if (p > (LPVOID)new_limit /* overflow */) break;
1344 p = (LPVOID)new_limit;
1346 if (base != limit) GC_add_roots_inner(base, limit, FALSE);
1350 void GC_register_data_segments()
1354 GC_register_root_section((ptr_t)(&dummy));
1358 # else /* !OS2 && !Windows */
1360 # if (defined(SVR4) || defined(AUX) || defined(DGUX) \
1361 || (defined(LINUX) && defined(SPARC))) && !defined(PCR)
1362 ptr_t GC_SysVGetDataStart(max_page_size, etext_addr)
1366 word text_end = ((word)(etext_addr) + sizeof(word) - 1)
1367 & ~(sizeof(word) - 1);
1368 /* etext rounded to word boundary */
1369 word next_page = ((text_end + (word)max_page_size - 1)
1370 & ~((word)max_page_size - 1));
1371 word page_offset = (text_end & ((word)max_page_size - 1));
1372 VOLATILE char * result = (char *)(next_page + page_offset);
1373 /* Note that this isnt equivalent to just adding */
1374 /* max_page_size to &etext if &etext is at a page boundary */
1376 GC_setup_temporary_fault_handler();
1377 if (SETJMP(GC_jmp_buf) == 0) {
1378 /* Try writing to the address. */
1380 GC_reset_fault_handler();
1382 GC_reset_fault_handler();
1383 /* We got here via a longjmp. The address is not readable. */
1384 /* This is known to happen under Solaris 2.4 + gcc, which place */
1385 /* string constants in the text segment, but after etext. */
1386 /* Use plan B. Note that we now know there is a gap between */
1387 /* text and data segments, so plan A bought us something. */
1388 result = (char *)GC_find_limit((ptr_t)(DATAEND), FALSE);
1390 return((ptr_t)result);
1394 # if defined(FREEBSD) && (defined(I386) || defined(powerpc) || defined(__powerpc__)) && !defined(PCR)
1395 /* Its unclear whether this should be identical to the above, or */
1396 /* whether it should apply to non-X86 architectures. */
1397 /* For now we don't assume that there is always an empty page after */
1398 /* etext. But in some cases there actually seems to be slightly more. */
1399 /* This also deals with holes between read-only data and writable data. */
1400 ptr_t GC_FreeBSDGetDataStart(max_page_size, etext_addr)
1404 word text_end = ((word)(etext_addr) + sizeof(word) - 1)
1405 & ~(sizeof(word) - 1);
1406 /* etext rounded to word boundary */
1407 VOLATILE word next_page = (text_end + (word)max_page_size - 1)
1408 & ~((word)max_page_size - 1);
1409 VOLATILE ptr_t result = (ptr_t)text_end;
1410 GC_setup_temporary_fault_handler();
1411 if (SETJMP(GC_jmp_buf) == 0) {
1412 /* Try reading at the address. */
1413 /* This should happen before there is another thread. */
1414 for (; next_page < (word)(DATAEND); next_page += (word)max_page_size)
1415 *(VOLATILE char *)next_page;
1416 GC_reset_fault_handler();
1418 GC_reset_fault_handler();
1419 /* As above, we go to plan B */
1420 result = GC_find_limit((ptr_t)(DATAEND), FALSE);
1430 # define GC_AMIGA_DS
1431 # include "AmigaOS.c"
1434 #else /* !OS2 && !Windows && !AMIGA */
1436 void GC_register_data_segments()
1438 # if !defined(PCR) && !defined(SRC_M3) && !defined(MACOS)
1439 # if defined(REDIRECT_MALLOC) && defined(GC_SOLARIS_THREADS)
1440 /* As of Solaris 2.3, the Solaris threads implementation */
1441 /* allocates the data structure for the initial thread with */
1442 /* sbrk at process startup. It needs to be scanned, so that */
1443 /* we don't lose some malloc allocated data structures */
1444 /* hanging from it. We're on thin ice here ... */
1445 extern caddr_t sbrk();
1447 GC_add_roots_inner(DATASTART, (char *)sbrk(0), FALSE);
1449 GC_add_roots_inner(DATASTART, (char *)(DATAEND), FALSE);
1450 # if defined(DATASTART2)
1451 GC_add_roots_inner(DATASTART2, (char *)(DATAEND2), FALSE);
1457 # if defined(THINK_C)
1458 extern void* GC_MacGetDataStart(void);
1459 /* globals begin above stack and end at a5. */
1460 GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
1461 (ptr_t)LMGetCurrentA5(), FALSE);
1463 # if defined(__MWERKS__)
1465 extern void* GC_MacGetDataStart(void);
1466 /* MATTHEW: Function to handle Far Globals (CW Pro 3) */
1467 # if __option(far_data)
1468 extern void* GC_MacGetDataEnd(void);
1470 /* globals begin above stack and end at a5. */
1471 GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
1472 (ptr_t)LMGetCurrentA5(), FALSE);
1473 /* MATTHEW: Handle Far Globals */
1474 # if __option(far_data)
1475 /* Far globals follow he QD globals: */
1476 GC_add_roots_inner((ptr_t)LMGetCurrentA5(),
1477 (ptr_t)GC_MacGetDataEnd(), FALSE);
1480 extern char __data_start__[], __data_end__[];
1481 GC_add_roots_inner((ptr_t)&__data_start__,
1482 (ptr_t)&__data_end__, FALSE);
1483 # endif /* __POWERPC__ */
1484 # endif /* __MWERKS__ */
1485 # endif /* !THINK_C */
1489 /* Dynamic libraries are added at every collection, since they may */
1493 # endif /* ! AMIGA */
1494 # endif /* ! MSWIN32 && ! MSWINCE*/
1498 * Auxiliary routines for obtaining memory from OS.
1501 # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) \
1502 && !defined(MSWIN32) && !defined(MSWINCE) \
1503 && !defined(MACOS) && !defined(DOS4GW)
1506 extern caddr_t sbrk();
1509 # define SBRK_ARG_T ptrdiff_t
1511 # define SBRK_ARG_T int
1515 # if 0 && defined(RS6000) /* We now use mmap */
1516 /* The compiler seems to generate speculative reads one past the end of */
1517 /* an allocated object. Hence we need to make sure that the page */
1518 /* following the last heap page is also mapped. */
1519 ptr_t GC_unix_get_mem(bytes)
1522 caddr_t cur_brk = (caddr_t)sbrk(0);
1524 SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1);
1525 static caddr_t my_brk_val = 0;
1527 if ((SBRK_ARG_T)bytes < 0) return(0); /* too big */
1529 if((caddr_t)(sbrk(GC_page_size - lsbs)) == (caddr_t)(-1)) return(0);
1531 if (cur_brk == my_brk_val) {
1532 /* Use the extra block we allocated last time. */
1533 result = (ptr_t)sbrk((SBRK_ARG_T)bytes);
1534 if (result == (caddr_t)(-1)) return(0);
1535 result -= GC_page_size;
1537 result = (ptr_t)sbrk(GC_page_size + (SBRK_ARG_T)bytes);
1538 if (result == (caddr_t)(-1)) return(0);
1540 my_brk_val = result + bytes + GC_page_size; /* Always page aligned */
1541 return((ptr_t)result);
1544 #else /* Not RS6000 */
1546 #if defined(USE_MMAP) || defined(USE_MUNMAP)
1548 #ifdef USE_MMAP_FIXED
1549 # define GC_MMAP_FLAGS MAP_FIXED | MAP_PRIVATE
1550 /* Seems to yield better performance on Solaris 2, but can */
1551 /* be unreliable if something is already mapped at the address. */
1553 # define GC_MMAP_FLAGS MAP_PRIVATE
1556 #ifdef USE_MMAP_ANON
1558 # if defined(MAP_ANONYMOUS)
1559 # define OPT_MAP_ANON MAP_ANONYMOUS
1561 # define OPT_MAP_ANON MAP_ANON
1565 # define OPT_MAP_ANON 0
1568 #endif /* defined(USE_MMAP) || defined(USE_MUNMAP) */
1570 #if defined(USE_MMAP)
1571 /* Tested only under Linux, IRIX5 and Solaris 2 */
1574 # define HEAP_START 0
1577 ptr_t GC_unix_get_mem(bytes)
1581 static ptr_t last_addr = HEAP_START;
1583 # ifndef USE_MMAP_ANON
1584 static GC_bool initialized = FALSE;
1587 zero_fd = open("/dev/zero", O_RDONLY);
1588 fcntl(zero_fd, F_SETFD, FD_CLOEXEC);
1593 if (bytes & (GC_page_size -1)) ABORT("Bad GET_MEM arg");
1594 result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC,
1595 GC_MMAP_FLAGS | OPT_MAP_ANON, zero_fd, 0/* offset */);
1596 if (result == MAP_FAILED) return(0);
1597 last_addr = (ptr_t)result + bytes + GC_page_size - 1;
1598 last_addr = (ptr_t)((word)last_addr & ~(GC_page_size - 1));
1599 # if !defined(LINUX)
1600 if (last_addr == 0) {
1601 /* Oops. We got the end of the address space. This isn't */
1602 /* usable by arbitrary C code, since one-past-end pointers */
1603 /* don't work, so we discard it and try again. */
1604 munmap(result, (size_t)(-GC_page_size) - (size_t)result);
1605 /* Leave last page mapped, so we can't repeat. */
1606 return GC_unix_get_mem(bytes);
1609 GC_ASSERT(last_addr != 0);
1611 return((ptr_t)result);
1614 #else /* Not RS6000, not USE_MMAP */
1615 ptr_t GC_unix_get_mem(bytes)
1620 /* Bare sbrk isn't thread safe. Play by malloc rules. */
1621 /* The equivalent may be needed on other systems as well. */
1625 ptr_t cur_brk = (ptr_t)sbrk(0);
1626 SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1);
1628 if ((SBRK_ARG_T)bytes < 0) return(0); /* too big */
1630 if((ptr_t)sbrk(GC_page_size - lsbs) == (ptr_t)(-1)) return(0);
1632 result = (ptr_t)sbrk((SBRK_ARG_T)bytes);
1633 if (result == (ptr_t)(-1)) result = 0;
1641 #endif /* Not USE_MMAP */
1642 #endif /* Not RS6000 */
1648 void * os2_alloc(size_t bytes)
1652 if (DosAllocMem(&result, bytes, PAG_EXECUTE | PAG_READ |
1653 PAG_WRITE | PAG_COMMIT)
1657 if (result == 0) return(os2_alloc(bytes));
1664 # if defined(MSWIN32) || defined(MSWINCE)
1665 SYSTEM_INFO GC_sysinfo;
1670 # ifdef USE_GLOBAL_ALLOC
1671 # define GLOBAL_ALLOC_TEST 1
1673 # define GLOBAL_ALLOC_TEST GC_no_win32_dlls
1676 word GC_n_heap_bases = 0;
1678 ptr_t GC_win32_get_mem(bytes)
1683 if (GLOBAL_ALLOC_TEST) {
1684 /* VirtualAlloc doesn't like PAGE_EXECUTE_READWRITE. */
1685 /* There are also unconfirmed rumors of other */
1686 /* problems, so we dodge the issue. */
1687 result = (ptr_t) GlobalAlloc(0, bytes + HBLKSIZE);
1688 result = (ptr_t)(((word)result + HBLKSIZE) & ~(HBLKSIZE-1));
1690 /* VirtualProtect only works on regions returned by a */
1691 /* single VirtualAlloc call. Thus we allocate one */
1692 /* extra page, which will prevent merging of blocks */
1693 /* in separate regions, and eliminate any temptation */
1694 /* to call VirtualProtect on a range spanning regions. */
1695 /* This wastes a small amount of memory, and risks */
1696 /* increased fragmentation. But better alternatives */
1697 /* would require effort. */
1698 result = (ptr_t) VirtualAlloc(NULL, bytes + 1,
1699 MEM_COMMIT | MEM_RESERVE,
1700 PAGE_EXECUTE_READWRITE);
1702 if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
1703 /* If I read the documentation correctly, this can */
1704 /* only happen if HBLKSIZE > 64k or not a power of 2. */
1705 if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
1706 GC_heap_bases[GC_n_heap_bases++] = result;
1710 void GC_win32_free_heap ()
1712 if (GC_no_win32_dlls) {
1713 while (GC_n_heap_bases > 0) {
1714 GlobalFree (GC_heap_bases[--GC_n_heap_bases]);
1715 GC_heap_bases[GC_n_heap_bases] = 0;
1722 # define GC_AMIGA_AM
1723 # include "AmigaOS.c"
1729 word GC_n_heap_bases = 0;
1731 ptr_t GC_wince_get_mem(bytes)
1737 /* Round up allocation size to multiple of page size */
1738 bytes = (bytes + GC_page_size-1) & ~(GC_page_size-1);
1740 /* Try to find reserved, uncommitted pages */
1741 for (i = 0; i < GC_n_heap_bases; i++) {
1742 if (((word)(-(signed_word)GC_heap_lengths[i])
1743 & (GC_sysinfo.dwAllocationGranularity-1))
1745 result = GC_heap_bases[i] + GC_heap_lengths[i];
1750 if (i == GC_n_heap_bases) {
1751 /* Reserve more pages */
1752 word res_bytes = (bytes + GC_sysinfo.dwAllocationGranularity-1)
1753 & ~(GC_sysinfo.dwAllocationGranularity-1);
1754 /* If we ever support MPROTECT_VDB here, we will probably need to */
1755 /* ensure that res_bytes is strictly > bytes, so that VirtualProtect */
1756 /* never spans regions. It seems to be OK for a VirtualFree argument */
1757 /* to span regions, so we should be OK for now. */
1758 result = (ptr_t) VirtualAlloc(NULL, res_bytes,
1759 MEM_RESERVE | MEM_TOP_DOWN,
1760 PAGE_EXECUTE_READWRITE);
1761 if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
1762 /* If I read the documentation correctly, this can */
1763 /* only happen if HBLKSIZE > 64k or not a power of 2. */
1764 if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
1765 GC_heap_bases[GC_n_heap_bases] = result;
1766 GC_heap_lengths[GC_n_heap_bases] = 0;
1771 result = (ptr_t) VirtualAlloc(result, bytes,
1773 PAGE_EXECUTE_READWRITE);
1774 if (result != NULL) {
1775 if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
1776 GC_heap_lengths[i] += bytes;
1785 /* For now, this only works on Win32/WinCE and some Unix-like */
1786 /* systems. If you have something else, don't define */
1788 /* We assume ANSI C to support this feature. */
1790 #if !defined(MSWIN32) && !defined(MSWINCE)
1793 #include <sys/mman.h>
1794 #include <sys/stat.h>
1795 #include <sys/types.h>
1799 /* Compute a page aligned starting address for the unmap */
1800 /* operation on a block of size bytes starting at start. */
1801 /* Return 0 if the block is too small to make this feasible. */
1802 ptr_t GC_unmap_start(ptr_t start, word bytes)
1804 ptr_t result = start;
1805 /* Round start to next page boundary. */
1806 result += GC_page_size - 1;
1807 result = (ptr_t)((word)result & ~(GC_page_size - 1));
1808 if (result + GC_page_size > start + bytes) return 0;
1812 /* Compute end address for an unmap operation on the indicated */
1814 ptr_t GC_unmap_end(ptr_t start, word bytes)
1816 ptr_t end_addr = start + bytes;
1817 end_addr = (ptr_t)((word)end_addr & ~(GC_page_size - 1));
1821 /* Under Win32/WinCE we commit (map) and decommit (unmap) */
1822 /* memory using VirtualAlloc and VirtualFree. These functions */
1823 /* work on individual allocations of virtual memory, made */
1824 /* previously using VirtualAlloc with the MEM_RESERVE flag. */
1825 /* The ranges we need to (de)commit may span several of these */
1826 /* allocations; therefore we use VirtualQuery to check */
1827 /* allocation lengths, and split up the range as necessary. */
1829 /* We assume that GC_remap is called on exactly the same range */
1830 /* as a previous call to GC_unmap. It is safe to consistently */
1831 /* round the endpoints in both places. */
1832 void GC_unmap(ptr_t start, word bytes)
1834 ptr_t start_addr = GC_unmap_start(start, bytes);
1835 ptr_t end_addr = GC_unmap_end(start, bytes);
1836 word len = end_addr - start_addr;
1837 if (0 == start_addr) return;
1838 # if defined(MSWIN32) || defined(MSWINCE)
1840 MEMORY_BASIC_INFORMATION mem_info;
1842 if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
1843 != sizeof(mem_info))
1844 ABORT("Weird VirtualQuery result");
1845 free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
1846 if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
1847 ABORT("VirtualFree failed");
1848 GC_unmapped_bytes += free_len;
1849 start_addr += free_len;
1853 /* We immediately remap it to prevent an intervening mmap from */
1854 /* accidentally grabbing the same address space. */
1857 result = mmap(start_addr, len, PROT_NONE,
1858 MAP_PRIVATE | MAP_FIXED | OPT_MAP_ANON,
1859 zero_fd, 0/* offset */);
1860 if (result != (void *)start_addr) ABORT("mmap(...PROT_NONE...) failed");
1862 GC_unmapped_bytes += len;
1867 void GC_remap(ptr_t start, word bytes)
1869 ptr_t start_addr = GC_unmap_start(start, bytes);
1870 ptr_t end_addr = GC_unmap_end(start, bytes);
1871 word len = end_addr - start_addr;
1873 # if defined(MSWIN32) || defined(MSWINCE)
1876 if (0 == start_addr) return;
1878 MEMORY_BASIC_INFORMATION mem_info;
1880 if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
1881 != sizeof(mem_info))
1882 ABORT("Weird VirtualQuery result");
1883 alloc_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
1884 result = VirtualAlloc(start_addr, alloc_len,
1886 PAGE_EXECUTE_READWRITE);
1887 if (result != start_addr) {
1888 ABORT("VirtualAlloc remapping failed");
1890 GC_unmapped_bytes -= alloc_len;
1891 start_addr += alloc_len;
1895 /* It was already remapped with PROT_NONE. */
1898 if (0 == start_addr) return;
1899 result = mprotect(start_addr, len,
1900 PROT_READ | PROT_WRITE | OPT_PROT_EXEC);
1903 "Mprotect failed at 0x%lx (length %ld) with errno %ld\n",
1904 start_addr, len, errno);
1905 ABORT("Mprotect remapping failed");
1907 GC_unmapped_bytes -= len;
1911 /* Two adjacent blocks have already been unmapped and are about to */
1912 /* be merged. Unmap the whole block. This typically requires */
1913 /* that we unmap a small section in the middle that was not previously */
1914 /* unmapped due to alignment constraints. */
1915 void GC_unmap_gap(ptr_t start1, word bytes1, ptr_t start2, word bytes2)
1917 ptr_t start1_addr = GC_unmap_start(start1, bytes1);
1918 ptr_t end1_addr = GC_unmap_end(start1, bytes1);
1919 ptr_t start2_addr = GC_unmap_start(start2, bytes2);
1920 ptr_t end2_addr = GC_unmap_end(start2, bytes2);
1921 ptr_t start_addr = end1_addr;
1922 ptr_t end_addr = start2_addr;
1924 GC_ASSERT(start1 + bytes1 == start2);
1925 if (0 == start1_addr) start_addr = GC_unmap_start(start1, bytes1 + bytes2);
1926 if (0 == start2_addr) end_addr = GC_unmap_end(start1, bytes1 + bytes2);
1927 if (0 == start_addr) return;
1928 len = end_addr - start_addr;
1929 # if defined(MSWIN32) || defined(MSWINCE)
1931 MEMORY_BASIC_INFORMATION mem_info;
1933 if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
1934 != sizeof(mem_info))
1935 ABORT("Weird VirtualQuery result");
1936 free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
1937 if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
1938 ABORT("VirtualFree failed");
1939 GC_unmapped_bytes += free_len;
1940 start_addr += free_len;
1944 if (len != 0 && munmap(start_addr, len) != 0) ABORT("munmap failed");
1945 GC_unmapped_bytes += len;
1949 #endif /* USE_MUNMAP */
1951 /* Routine for pushing any additional roots. In THREADS */
1952 /* environment, this is also responsible for marking from */
1953 /* thread stacks. */
1955 void (*GC_push_other_roots)() = 0;
1959 PCR_ERes GC_push_thread_stack(PCR_Th_T *t, PCR_Any dummy)
1961 struct PCR_ThCtl_TInfoRep info;
1964 info.ti_stkLow = info.ti_stkHi = 0;
1965 result = PCR_ThCtl_GetInfo(t, &info);
1966 GC_push_all_stack((ptr_t)(info.ti_stkLow), (ptr_t)(info.ti_stkHi));
1970 /* Push the contents of an old object. We treat this as stack */
1971 /* data only becasue that makes it robust against mark stack */
1973 PCR_ERes GC_push_old_obj(void *p, size_t size, PCR_Any data)
1975 GC_push_all_stack((ptr_t)p, (ptr_t)p + size);
1976 return(PCR_ERes_okay);
1980 void GC_default_push_other_roots GC_PROTO((void))
1982 /* Traverse data allocated by previous memory managers. */
1984 extern struct PCR_MM_ProcsRep * GC_old_allocator;
1986 if ((*(GC_old_allocator->mmp_enumerate))(PCR_Bool_false,
1989 ABORT("Old object enumeration failed");
1992 /* Traverse all thread stacks. */
1994 PCR_ThCtl_ApplyToAllOtherThreads(GC_push_thread_stack,0))
1995 || PCR_ERes_IsErr(GC_push_thread_stack(PCR_Th_CurrThread(), 0))) {
1996 ABORT("Thread stack marking failed\n");
2004 # ifdef ALL_INTERIOR_POINTERS
2008 void GC_push_thread_structures GC_PROTO((void))
2010 /* Not our responsibibility. */
2013 extern void ThreadF__ProcessStacks();
2015 void GC_push_thread_stack(start, stop)
2018 GC_push_all_stack((ptr_t)start, (ptr_t)stop + sizeof(word));
2021 /* Push routine with M3 specific calling convention. */
2022 GC_m3_push_root(dummy1, p, dummy2, dummy3)
2024 ptr_t dummy1, dummy2;
2029 GC_PUSH_ONE_STACK(q, p);
2032 /* M3 set equivalent to RTHeap.TracedRefTypes */
2033 typedef struct { int elts[1]; } RefTypeSet;
2034 RefTypeSet GC_TracedRefTypes = {{0x1}};
2036 void GC_default_push_other_roots GC_PROTO((void))
2038 /* Use the M3 provided routine for finding static roots. */
2039 /* This is a bit dubious, since it presumes no C roots. */
2040 /* We handle the collector roots explicitly in GC_push_roots */
2041 RTMain__GlobalMapProc(GC_m3_push_root, 0, GC_TracedRefTypes);
2042 if (GC_words_allocd > 0) {
2043 ThreadF__ProcessStacks(GC_push_thread_stack);
2045 /* Otherwise this isn't absolutely necessary, and we have */
2046 /* startup ordering problems. */
2049 # endif /* SRC_M3 */
2051 # if defined(GC_SOLARIS_THREADS) || defined(GC_PTHREADS) || \
2052 defined(GC_WIN32_THREADS)
2054 extern void GC_push_all_stacks();
2056 void GC_default_push_other_roots GC_PROTO((void))
2058 GC_push_all_stacks();
2061 # endif /* GC_SOLARIS_THREADS || GC_PTHREADS */
2063 void (*GC_push_other_roots) GC_PROTO((void)) = GC_default_push_other_roots;
2065 #endif /* THREADS */
2068 * Routines for accessing dirty bits on virtual pages.
2069 * We plan to eventually implement four strategies for doing so:
2070 * DEFAULT_VDB: A simple dummy implementation that treats every page
2071 * as possibly dirty. This makes incremental collection
2072 * useless, but the implementation is still correct.
2073 * PCR_VDB: Use PPCRs virtual dirty bit facility.
2074 * PROC_VDB: Use the /proc facility for reading dirty bits. Only
2075 * works under some SVR4 variants. Even then, it may be
2076 * too slow to be entirely satisfactory. Requires reading
2077 * dirty bits for entire address space. Implementations tend
2078 * to assume that the client is a (slow) debugger.
2079 * MPROTECT_VDB:Protect pages and then catch the faults to keep track of
2080 * dirtied pages. The implementation (and implementability)
2081 * is highly system dependent. This usually fails when system
2082 * calls write to a protected page. We prevent the read system
2083 * call from doing so. It is the clients responsibility to
2084 * make sure that other system calls are similarly protected
2085 * or write only to the stack.
2087 GC_bool GC_dirty_maintained = FALSE;
2091 /* All of the following assume the allocation lock is held, and */
2092 /* signals are disabled. */
2094 /* The client asserts that unallocated pages in the heap are never */
2097 /* Initialize virtual dirty bit implementation. */
2098 void GC_dirty_init()
2101 GC_printf0("Initializing DEFAULT_VDB...\n");
2103 GC_dirty_maintained = TRUE;
2106 /* Retrieve system dirty bits for heap to a local buffer. */
2107 /* Restore the systems notion of which pages are dirty. */
2108 void GC_read_dirty()
2111 /* Is the HBLKSIZE sized page at h marked dirty in the local buffer? */
2112 /* If the actual page size is different, this returns TRUE if any */
2113 /* of the pages overlapping h are dirty. This routine may err on the */
2114 /* side of labelling pages as dirty (and this implementation does). */
2116 GC_bool GC_page_was_dirty(h)
2123 * The following two routines are typically less crucial. They matter
2124 * most with large dynamic libraries, or if we can't accurately identify
2125 * stacks, e.g. under Solaris 2.X. Otherwise the following default
2126 * versions are adequate.
2129 /* Could any valid GC heap pointer ever have been written to this page? */
2131 GC_bool GC_page_was_ever_dirty(h)
2137 /* Reset the n pages starting at h to "was never dirty" status. */
2138 void GC_is_fresh(h, n)
2145 /* I) hints that [h, h+nblocks) is about to be written. */
2146 /* II) guarantees that protection is removed. */
2147 /* (I) may speed up some dirty bit implementations. */
2148 /* (II) may be essential if we need to ensure that */
2149 /* pointer-free system call buffers in the heap are */
2150 /* not protected. */
2152 void GC_remove_protection(h, nblocks, is_ptrfree)
2159 # endif /* DEFAULT_VDB */
2162 # ifdef MPROTECT_VDB
2165 * See DEFAULT_VDB for interface descriptions.
2169 * This implementation maintains dirty bits itself by catching write
2170 * faults and keeping track of them. We assume nobody else catches
2171 * SIGBUS or SIGSEGV. We assume no write faults occur in system calls.
2172 * This means that clients must ensure that system calls don't write
2173 * to the write-protected heap. Probably the best way to do this is to
2174 * ensure that system calls write at most to POINTERFREE objects in the
2175 * heap, and do even that only if we are on a platform on which those
2176 * are not protected. Another alternative is to wrap system calls
2177 * (see example for read below), but the current implementation holds
2178 * a lock across blocking calls, making it problematic for multithreaded
2180 * We assume the page size is a multiple of HBLKSIZE.
2181 * We prefer them to be the same. We avoid protecting POINTERFREE
2182 * objects only if they are the same.
2185 # if !defined(MSWIN32) && !defined(MSWINCE) && !defined(DARWIN)
2187 # include <sys/mman.h>
2188 # include <signal.h>
2189 # include <sys/syscall.h>
2191 # define PROTECT(addr, len) \
2192 if (mprotect((caddr_t)(addr), (size_t)(len), \
2193 PROT_READ | OPT_PROT_EXEC) < 0) { \
2194 ABORT("mprotect failed"); \
2196 # define UNPROTECT(addr, len) \
2197 if (mprotect((caddr_t)(addr), (size_t)(len), \
2198 PROT_WRITE | PROT_READ | OPT_PROT_EXEC ) < 0) { \
2199 ABORT("un-mprotect failed"); \
2205 /* Using vm_protect (mach syscall) over mprotect (BSD syscall) seems to
2206 decrease the likelihood of some of the problems described below. */
2207 #include <mach/vm_map.h>
2208 static mach_port_t GC_task_self;
2209 #define PROTECT(addr,len) \
2210 if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \
2211 FALSE,VM_PROT_READ) != KERN_SUCCESS) { \
2212 ABORT("vm_portect failed"); \
2214 #define UNPROTECT(addr,len) \
2215 if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \
2216 FALSE,VM_PROT_READ|VM_PROT_WRITE) != KERN_SUCCESS) { \
2217 ABORT("vm_portect failed"); \
2222 # include <signal.h>
2225 static DWORD protect_junk;
2226 # define PROTECT(addr, len) \
2227 if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READ, \
2229 DWORD last_error = GetLastError(); \
2230 GC_printf1("Last error code: %lx\n", last_error); \
2231 ABORT("VirtualProtect failed"); \
2233 # define UNPROTECT(addr, len) \
2234 if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READWRITE, \
2236 ABORT("un-VirtualProtect failed"); \
2238 # endif /* !DARWIN */
2239 # endif /* MSWIN32 || MSWINCE || DARWIN */
2241 #if defined(SUNOS4) || (defined(FREEBSD) && !defined(SUNOS5SIGS))
2242 typedef void (* SIG_PF)();
2243 #endif /* SUNOS4 || (FREEBSD && !SUNOS5SIGS) */
2245 #if defined(SUNOS5SIGS) || defined(OSF1) || defined(LINUX) \
2248 typedef void (* SIG_PF)(int);
2250 typedef void (* SIG_PF)();
2252 #endif /* SUNOS5SIGS || OSF1 || LINUX || HURD */
2254 #if defined(MSWIN32)
2255 typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_PF;
2257 # define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER) (-1)
2259 #if defined(MSWINCE)
2260 typedef LONG (WINAPI *SIG_PF)(struct _EXCEPTION_POINTERS *);
2262 # define SIG_DFL (SIG_PF) (-1)
2265 #if defined(IRIX5) || defined(OSF1) || defined(HURD)
2266 typedef void (* REAL_SIG_PF)(int, int, struct sigcontext *);
2267 #endif /* IRIX5 || OSF1 || HURD */
2269 #if defined(SUNOS5SIGS)
2270 # if defined(HPUX) || defined(FREEBSD)
2271 # define SIGINFO_T siginfo_t
2273 # define SIGINFO_T struct siginfo
2276 typedef void (* REAL_SIG_PF)(int, SIGINFO_T *, void *);
2278 typedef void (* REAL_SIG_PF)();
2280 #endif /* SUNOS5SIGS */
2283 # if __GLIBC__ > 2 || __GLIBC__ == 2 && __GLIBC_MINOR__ >= 2
2284 typedef struct sigcontext s_c;
2285 # else /* glibc < 2.2 */
2286 # include <linux/version.h>
2287 # if (LINUX_VERSION_CODE >= 0x20100) && !defined(M68K) || defined(ALPHA) || defined(ARM32)
2288 typedef struct sigcontext s_c;
2290 typedef struct sigcontext_struct s_c;
2292 # endif /* glibc < 2.2 */
2293 # if defined(ALPHA) || defined(M68K)
2294 typedef void (* REAL_SIG_PF)(int, int, s_c *);
2296 # if defined(IA64) || defined(HP_PA) || defined(X86_64)
2297 typedef void (* REAL_SIG_PF)(int, siginfo_t *, s_c *);
2299 /* According to SUSV3, the last argument should have type */
2300 /* void * or ucontext_t * */
2302 typedef void (* REAL_SIG_PF)(int, s_c);
2306 /* Retrieve fault address from sigcontext structure by decoding */
2308 char * get_fault_addr(s_c *sc) {
2312 instr = *((unsigned *)(sc->sc_pc));
2313 faultaddr = sc->sc_regs[(instr >> 16) & 0x1f];
2314 faultaddr += (word) (((int)instr << 16) >> 16);
2315 return (char *)faultaddr;
2317 # endif /* !ALPHA */
2321 SIG_PF GC_old_bus_handler;
2322 SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS_VIOLATION filter */
2323 #endif /* !DARWIN */
2325 #if defined(THREADS)
2326 /* We need to lock around the bitmap update in the write fault handler */
2327 /* in order to avoid the risk of losing a bit. We do this with a */
2328 /* test-and-set spin lock if we know how to do that. Otherwise we */
2329 /* check whether we are already in the handler and use the dumb but */
2330 /* safe fallback algorithm of setting all bits in the word. */
2331 /* Contention should be very rare, so we do the minimum to handle it */
2333 #ifdef GC_TEST_AND_SET_DEFINED
2334 static VOLATILE unsigned int fault_handler_lock = 0;
2335 void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) {
2336 while (GC_test_and_set(&fault_handler_lock)) {}
2337 /* Could also revert to set_pht_entry_from_index_safe if initial */
2338 /* GC_test_and_set fails. */
2339 set_pht_entry_from_index(db, index);
2340 GC_clear(&fault_handler_lock);
2342 #else /* !GC_TEST_AND_SET_DEFINED */
2343 /* THIS IS INCORRECT! The dirty bit vector may be temporarily wrong, */
2344 /* just before we notice the conflict and correct it. We may end up */
2345 /* looking at it while it's wrong. But this requires contention */
2346 /* exactly when a GC is triggered, which seems far less likely to */
2347 /* fail than the old code, which had no reported failures. Thus we */
2348 /* leave it this way while we think of something better, or support */
2349 /* GC_test_and_set on the remaining platforms. */
2350 static VOLATILE word currently_updating = 0;
2351 void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) {
2352 unsigned int update_dummy;
2353 currently_updating = (word)(&update_dummy);
2354 set_pht_entry_from_index(db, index);
2355 /* If we get contention in the 10 or so instruction window here, */
2356 /* and we get stopped by a GC between the two updates, we lose! */
2357 if (currently_updating != (word)(&update_dummy)) {
2358 set_pht_entry_from_index_safe(db, index);
2359 /* We claim that if two threads concurrently try to update the */
2360 /* dirty bit vector, the first one to execute UPDATE_START */
2361 /* will see it changed when UPDATE_END is executed. (Note that */
2362 /* &update_dummy must differ in two distinct threads.) It */
2363 /* will then execute set_pht_entry_from_index_safe, thus */
2364 /* returning us to a safe state, though not soon enough. */
2367 #endif /* !GC_TEST_AND_SET_DEFINED */
2368 #else /* !THREADS */
2369 # define async_set_pht_entry_from_index(db, index) \
2370 set_pht_entry_from_index(db, index)
2371 #endif /* !THREADS */
2374 #if !defined(DARWIN)
2375 # if defined (SUNOS4) || (defined(FREEBSD) && !defined(SUNOS5SIGS))
2376 void GC_write_fault_handler(sig, code, scp, addr)
2378 struct sigcontext *scp;
2381 # define SIG_OK (sig == SIGSEGV || sig == SIGBUS)
2382 # define CODE_OK (FC_CODE(code) == FC_PROT \
2383 || (FC_CODE(code) == FC_OBJERR \
2384 && FC_ERRNO(code) == FC_PROT))
2387 # define SIG_OK (sig == SIGBUS)
2388 # define CODE_OK TRUE
2390 # endif /* SUNOS4 || (FREEBSD && !SUNOS5SIGS) */
2392 # if defined(IRIX5) || defined(OSF1) || defined(HURD)
2394 void GC_write_fault_handler(int sig, int code, struct sigcontext *scp)
2396 # define SIG_OK (sig == SIGSEGV)
2397 # define CODE_OK (code == 2 /* experimentally determined */)
2400 # define SIG_OK (sig == SIGSEGV)
2401 # define CODE_OK (code == EACCES)
2404 # define SIG_OK (sig == SIGBUS || sig == SIGSEGV)
2405 # define CODE_OK TRUE
2407 # endif /* IRIX5 || OSF1 || HURD */
2410 # if defined(ALPHA) || defined(M68K)
2411 void GC_write_fault_handler(int sig, int code, s_c * sc)
2413 # if defined(IA64) || defined(HP_PA) || defined(X86_64)
2414 void GC_write_fault_handler(int sig, siginfo_t * si, s_c * scp)
2417 void GC_write_fault_handler(int sig, int a2, int a3, int a4, s_c sc)
2419 void GC_write_fault_handler(int sig, s_c sc)
2423 # define SIG_OK (sig == SIGSEGV)
2424 # define CODE_OK TRUE
2425 /* Empirically c.trapno == 14, on IA32, but is that useful? */
2426 /* Should probably consider alignment issues on other */
2427 /* architectures. */
2430 # if defined(SUNOS5SIGS)
2432 void GC_write_fault_handler(int sig, SIGINFO_T *scp, void * context)
2434 void GC_write_fault_handler(sig, scp, context)
2440 # define SIG_OK (sig == SIGSEGV || sig == SIGBUS)
2441 # define CODE_OK (scp -> si_code == SEGV_ACCERR) \
2442 || (scp -> si_code == BUS_ADRERR) \
2443 || (scp -> si_code == BUS_UNKNOWN) \
2444 || (scp -> si_code == SEGV_UNKNOWN) \
2445 || (scp -> si_code == BUS_OBJERR)
2448 # define SIG_OK (sig == SIGBUS)
2449 # define CODE_OK (scp -> si_code == BUS_PAGE_FAULT)
2451 # define SIG_OK (sig == SIGSEGV)
2452 # define CODE_OK (scp -> si_code == SEGV_ACCERR)
2455 # endif /* SUNOS5SIGS */
2457 # if defined(MSWIN32) || defined(MSWINCE)
2458 LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info)
2459 # define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode == \
2460 STATUS_ACCESS_VIOLATION)
2461 # define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] == 1)
2463 # endif /* MSWIN32 || MSWINCE */
2465 register unsigned i;
2467 char *addr = (char *) code;
2470 char * addr = (char *) (size_t) (scp -> sc_badvaddr);
2472 # if defined(OSF1) && defined(ALPHA)
2473 char * addr = (char *) (scp -> sc_traparg_a0);
2476 char * addr = (char *) (scp -> si_addr);
2480 char * addr = (char *) (sc.cr2);
2485 struct sigcontext *scp = (struct sigcontext *)(sc);
2487 int format = (scp->sc_formatvec >> 12) & 0xf;
2488 unsigned long *framedata = (unsigned long *)(scp + 1);
2491 if (format == 0xa || format == 0xb) {
2494 } else if (format == 7) {
2497 if (framedata[1] & 0x08000000) {
2498 /* correct addr on misaligned access */
2499 ea = (ea+4095)&(~4095);
2501 } else if (format == 4) {
2504 if (framedata[1] & 0x08000000) {
2505 /* correct addr on misaligned access */
2506 ea = (ea+4095)&(~4095);
2512 char * addr = get_fault_addr(sc);
2514 # if defined(IA64) || defined(HP_PA) || defined(X86_64)
2515 char * addr = si -> si_addr;
2516 /* I believe this is claimed to work on all platforms for */
2517 /* Linux 2.3.47 and later. Hopefully we don't have to */
2518 /* worry about earlier kernels on IA64. */
2520 # if defined(POWERPC)
2521 char * addr = (char *) (sc.regs->dar);
2524 char * addr = (char *)sc.fault_address;
2527 char * addr = (char *)sc.regs.csraddr;
2529 --> architecture not supported
2538 # if defined(MSWIN32) || defined(MSWINCE)
2539 char * addr = (char *) (exc_info -> ExceptionRecord
2540 -> ExceptionInformation[1]);
2541 # define sig SIGSEGV
2544 if (SIG_OK && CODE_OK) {
2545 register struct hblk * h =
2546 (struct hblk *)((word)addr & ~(GC_page_size-1));
2547 GC_bool in_allocd_block;
2550 /* Address is only within the correct physical page. */
2551 in_allocd_block = FALSE;
2552 for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
2553 if (HDR(h+i) != 0) {
2554 in_allocd_block = TRUE;
2558 in_allocd_block = (HDR(addr) != 0);
2560 if (!in_allocd_block) {
2561 /* FIXME - We should make sure that we invoke the */
2562 /* old handler with the appropriate calling */
2563 /* sequence, which often depends on SA_SIGINFO. */
2565 /* Heap blocks now begin and end on page boundaries */
2568 if (sig == SIGSEGV) {
2569 old_handler = GC_old_segv_handler;
2571 old_handler = GC_old_bus_handler;
2573 if (old_handler == SIG_DFL) {
2574 # if !defined(MSWIN32) && !defined(MSWINCE)
2575 GC_err_printf1("Segfault at 0x%lx\n", addr);
2576 ABORT("Unexpected bus error or segmentation fault");
2578 return(EXCEPTION_CONTINUE_SEARCH);
2581 # if defined (SUNOS4) \
2582 || (defined(FREEBSD) && !defined(SUNOS5SIGS))
2583 (*old_handler) (sig, code, scp, addr);
2586 # if defined (SUNOS5SIGS)
2588 * FIXME: For FreeBSD, this code should check if the
2589 * old signal handler used the traditional BSD style and
2590 * if so call it using that style.
2592 (*(REAL_SIG_PF)old_handler) (sig, scp, context);
2595 # if defined (LINUX)
2596 # if defined(ALPHA) || defined(M68K)
2597 (*(REAL_SIG_PF)old_handler) (sig, code, sc);
2599 # if defined(IA64) || defined(HP_PA) || defined(X86_64)
2600 (*(REAL_SIG_PF)old_handler) (sig, si, scp);
2602 (*(REAL_SIG_PF)old_handler) (sig, sc);
2607 # if defined (IRIX5) || defined(OSF1) || defined(HURD)
2608 (*(REAL_SIG_PF)old_handler) (sig, code, scp);
2612 return((*old_handler)(exc_info));
2616 UNPROTECT(h, GC_page_size);
2617 /* We need to make sure that no collection occurs between */
2618 /* the UNPROTECT and the setting of the dirty bit. Otherwise */
2619 /* a write by a third thread might go unnoticed. Reversing */
2620 /* the order is just as bad, since we would end up unprotecting */
2621 /* a page in a GC cycle during which it's not marked. */
2622 /* Currently we do this by disabling the thread stopping */
2623 /* signals while this handler is running. An alternative might */
2624 /* be to record the fact that we're about to unprotect, or */
2625 /* have just unprotected a page in the GC's thread structure, */
2626 /* and then to have the thread stopping code set the dirty */
2627 /* flag, if necessary. */
2628 for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
2629 register int index = PHT_HASH(h+i);
2631 async_set_pht_entry_from_index(GC_dirty_pages, index);
2634 /* These reset the signal handler each time by default. */
2635 signal(SIGSEGV, (SIG_PF) GC_write_fault_handler);
2637 /* The write may not take place before dirty bits are read. */
2638 /* But then we'll fault again ... */
2639 # if defined(MSWIN32) || defined(MSWINCE)
2640 return(EXCEPTION_CONTINUE_EXECUTION);
2645 #if defined(MSWIN32) || defined(MSWINCE)
2646 return EXCEPTION_CONTINUE_SEARCH;
2648 GC_err_printf1("Segfault at 0x%lx\n", addr);
2649 ABORT("Unexpected bus error or segmentation fault");
2652 #endif /* !DARWIN */
2655 * We hold the allocation lock. We expect block h to be written
2656 * shortly. Ensure that all pages containing any part of the n hblks
2657 * starting at h are no longer protected. If is_ptrfree is false,
2658 * also ensure that they will subsequently appear to be dirty.
2660 void GC_remove_protection(h, nblocks, is_ptrfree)
2665 struct hblk * h_trunc; /* Truncated to page boundary */
2666 struct hblk * h_end; /* Page boundary following block end */
2667 struct hblk * current;
2668 GC_bool found_clean;
2670 if (!GC_dirty_maintained) return;
2671 h_trunc = (struct hblk *)((word)h & ~(GC_page_size-1));
2672 h_end = (struct hblk *)(((word)(h + nblocks) + GC_page_size-1)
2673 & ~(GC_page_size-1));
2674 found_clean = FALSE;
2675 for (current = h_trunc; current < h_end; ++current) {
2676 int index = PHT_HASH(current);
2678 if (!is_ptrfree || current < h || current >= h + nblocks) {
2679 async_set_pht_entry_from_index(GC_dirty_pages, index);
2682 UNPROTECT(h_trunc, (ptr_t)h_end - (ptr_t)h_trunc);
2685 #if !defined(DARWIN)
2686 void GC_dirty_init()
2688 # if defined(SUNOS5SIGS) || defined(IRIX5) || defined(LINUX) || \
2689 defined(OSF1) || defined(HURD)
2690 struct sigaction act, oldact;
2691 /* We should probably specify SA_SIGINFO for Linux, and handle */
2692 /* the different architectures more uniformly. */
2693 # if defined(IRIX5) || defined(LINUX) && !defined(X86_64) \
2694 || defined(OSF1) || defined(HURD)
2695 act.sa_flags = SA_RESTART;
2696 act.sa_handler = (SIG_PF)GC_write_fault_handler;
2698 act.sa_flags = SA_RESTART | SA_SIGINFO;
2699 act.sa_sigaction = GC_write_fault_handler;
2701 (void)sigemptyset(&act.sa_mask);
2703 /* Arrange to postpone SIG_SUSPEND while we're in a write fault */
2704 /* handler. This effectively makes the handler atomic w.r.t. */
2705 /* stopping the world for GC. */
2706 (void)sigaddset(&act.sa_mask, SIG_SUSPEND);
2707 # endif /* SIG_SUSPEND */
2710 GC_printf0("Inititalizing mprotect virtual dirty bit implementation\n");
2712 GC_dirty_maintained = TRUE;
2713 if (GC_page_size % HBLKSIZE != 0) {
2714 GC_err_printf0("Page size not multiple of HBLKSIZE\n");
2715 ABORT("Page size not multiple of HBLKSIZE");
2717 # if defined(SUNOS4) || (defined(FREEBSD) && !defined(SUNOS5SIGS))
2718 GC_old_bus_handler = signal(SIGBUS, GC_write_fault_handler);
2719 if (GC_old_bus_handler == SIG_IGN) {
2720 GC_err_printf0("Previously ignored bus error!?");
2721 GC_old_bus_handler = SIG_DFL;
2723 if (GC_old_bus_handler != SIG_DFL) {
2725 GC_err_printf0("Replaced other SIGBUS handler\n");
2729 # if defined(SUNOS4)
2730 GC_old_segv_handler = signal(SIGSEGV, (SIG_PF)GC_write_fault_handler);
2731 if (GC_old_segv_handler == SIG_IGN) {
2732 GC_err_printf0("Previously ignored segmentation violation!?");
2733 GC_old_segv_handler = SIG_DFL;
2735 if (GC_old_segv_handler != SIG_DFL) {
2737 GC_err_printf0("Replaced other SIGSEGV handler\n");
2741 # if (defined(SUNOS5SIGS) && !defined(FREEBSD)) || defined(IRIX5) \
2742 || defined(LINUX) || defined(OSF1) || defined(HURD)
2743 /* SUNOS5SIGS includes HPUX */
2744 # if defined(GC_IRIX_THREADS)
2745 sigaction(SIGSEGV, 0, &oldact);
2746 sigaction(SIGSEGV, &act, 0);
2749 int res = sigaction(SIGSEGV, &act, &oldact);
2750 if (res != 0) ABORT("Sigaction failed");
2753 # if defined(_sigargs) || defined(HURD) || !defined(SA_SIGINFO)
2754 /* This is Irix 5.x, not 6.x. Irix 5.x does not have */
2756 GC_old_segv_handler = oldact.sa_handler;
2757 # else /* Irix 6.x or SUNOS5SIGS or LINUX */
2758 if (oldact.sa_flags & SA_SIGINFO) {
2759 GC_old_segv_handler = (SIG_PF)(oldact.sa_sigaction);
2761 GC_old_segv_handler = oldact.sa_handler;
2764 if (GC_old_segv_handler == SIG_IGN) {
2765 GC_err_printf0("Previously ignored segmentation violation!?");
2766 GC_old_segv_handler = SIG_DFL;
2768 if (GC_old_segv_handler != SIG_DFL) {
2770 GC_err_printf0("Replaced other SIGSEGV handler\n");
2773 # endif /* (SUNOS5SIGS && !FREEBSD) || IRIX5 || LINUX || OSF1 || HURD */
2774 # if defined(HPUX) || defined(LINUX) || defined(HURD) \
2775 || (defined(FREEBSD) && defined(SUNOS5SIGS))
2776 sigaction(SIGBUS, &act, &oldact);
2777 GC_old_bus_handler = oldact.sa_handler;
2778 if (GC_old_bus_handler == SIG_IGN) {
2779 GC_err_printf0("Previously ignored bus error!?");
2780 GC_old_bus_handler = SIG_DFL;
2782 if (GC_old_bus_handler != SIG_DFL) {
2784 GC_err_printf0("Replaced other SIGBUS handler\n");
2787 # endif /* HPUX || LINUX || HURD || (FREEBSD && SUNOS5SIGS) */
2788 # if defined(MSWIN32)
2789 GC_old_segv_handler = SetUnhandledExceptionFilter(GC_write_fault_handler);
2790 if (GC_old_segv_handler != NULL) {
2792 GC_err_printf0("Replaced other UnhandledExceptionFilter\n");
2795 GC_old_segv_handler = SIG_DFL;
2799 #endif /* !DARWIN */
2801 int GC_incremental_protection_needs()
2803 if (GC_page_size == HBLKSIZE) {
2804 return GC_PROTECTS_POINTER_HEAP;
2806 return GC_PROTECTS_POINTER_HEAP | GC_PROTECTS_PTRFREE_HEAP;
2810 #define HAVE_INCREMENTAL_PROTECTION_NEEDS
2812 #define IS_PTRFREE(hhdr) ((hhdr)->hb_descr == 0)
2814 #define PAGE_ALIGNED(x) !((word)(x) & (GC_page_size - 1))
2815 void GC_protect_heap()
2819 struct hblk * current;
2820 struct hblk * current_start; /* Start of block to be protected. */
2821 struct hblk * limit;
2823 GC_bool protect_all =
2824 (0 != (GC_incremental_protection_needs() & GC_PROTECTS_PTRFREE_HEAP));
2825 for (i = 0; i < GC_n_heap_sects; i++) {
2826 start = GC_heap_sects[i].hs_start;
2827 len = GC_heap_sects[i].hs_bytes;
2829 PROTECT(start, len);
2831 GC_ASSERT(PAGE_ALIGNED(len))
2832 GC_ASSERT(PAGE_ALIGNED(start))
2833 current_start = current = (struct hblk *)start;
2834 limit = (struct hblk *)(start + len);
2835 while (current < limit) {
2840 GC_ASSERT(PAGE_ALIGNED(current));
2841 GET_HDR(current, hhdr);
2842 if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
2843 /* This can happen only if we're at the beginning of a */
2844 /* heap segment, and a block spans heap segments. */
2845 /* We will handle that block as part of the preceding */
2847 GC_ASSERT(current_start == current);
2848 current_start = ++current;
2851 if (HBLK_IS_FREE(hhdr)) {
2852 GC_ASSERT(PAGE_ALIGNED(hhdr -> hb_sz));
2853 nhblks = divHBLKSZ(hhdr -> hb_sz);
2854 is_ptrfree = TRUE; /* dirty on alloc */
2856 nhblks = OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz);
2857 is_ptrfree = IS_PTRFREE(hhdr);
2860 if (current_start < current) {
2861 PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
2863 current_start = (current += nhblks);
2868 if (current_start < current) {
2869 PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
2875 /* We assume that either the world is stopped or its OK to lose dirty */
2876 /* bits while this is happenning (as in GC_enable_incremental). */
2877 void GC_read_dirty()
2879 BCOPY((word *)GC_dirty_pages, GC_grungy_pages,
2880 (sizeof GC_dirty_pages));
2881 BZERO((word *)GC_dirty_pages, (sizeof GC_dirty_pages));
2885 GC_bool GC_page_was_dirty(h)
2888 register word index = PHT_HASH(h);
2890 return(HDR(h) == 0 || get_pht_entry_from_index(GC_grungy_pages, index));
2894 * Acquiring the allocation lock here is dangerous, since this
2895 * can be called from within GC_call_with_alloc_lock, and the cord
2896 * package does so. On systems that allow nested lock acquisition, this
2898 * On other systems, SET_LOCK_HOLDER and friends must be suitably defined.
2901 static GC_bool syscall_acquired_lock = FALSE; /* Protected by GC lock. */
2903 void GC_begin_syscall()
2905 if (!I_HOLD_LOCK()) {
2907 syscall_acquired_lock = TRUE;
2911 void GC_end_syscall()
2913 if (syscall_acquired_lock) {
2914 syscall_acquired_lock = FALSE;
2919 void GC_unprotect_range(addr, len)
2923 struct hblk * start_block;
2924 struct hblk * end_block;
2925 register struct hblk *h;
2928 if (!GC_dirty_maintained) return;
2929 obj_start = GC_base(addr);
2930 if (obj_start == 0) return;
2931 if (GC_base(addr + len - 1) != obj_start) {
2932 ABORT("GC_unprotect_range(range bigger than object)");
2934 start_block = (struct hblk *)((word)addr & ~(GC_page_size - 1));
2935 end_block = (struct hblk *)((word)(addr + len - 1) & ~(GC_page_size - 1));
2936 end_block += GC_page_size/HBLKSIZE - 1;
2937 for (h = start_block; h <= end_block; h++) {
2938 register word index = PHT_HASH(h);
2940 async_set_pht_entry_from_index(GC_dirty_pages, index);
2942 UNPROTECT(start_block,
2943 ((ptr_t)end_block - (ptr_t)start_block) + HBLKSIZE);
2948 /* We no longer wrap read by default, since that was causing too many */
2949 /* problems. It is preferred that the client instead avoids writing */
2950 /* to the write-protected heap with a system call. */
2951 /* This still serves as sample code if you do want to wrap system calls.*/
2953 #if !defined(MSWIN32) && !defined(MSWINCE) && !defined(GC_USE_LD_WRAP)
2954 /* Replacement for UNIX system call. */
2955 /* Other calls that write to the heap should be handled similarly. */
2956 /* Note that this doesn't work well for blocking reads: It will hold */
2957 /* the allocation lock for the entire duration of the call. Multithreaded */
2958 /* clients should really ensure that it won't block, either by setting */
2959 /* the descriptor nonblocking, or by calling select or poll first, to */
2960 /* make sure that input is available. */
2961 /* Another, preferred alternative is to ensure that system calls never */
2962 /* write to the protected heap (see above). */
2963 # if defined(__STDC__) && !defined(SUNOS4)
2964 # include <unistd.h>
2965 # include <sys/uio.h>
2966 ssize_t read(int fd, void *buf, size_t nbyte)
2969 int read(fd, buf, nbyte)
2971 int GC_read(fd, buf, nbyte)
2981 GC_unprotect_range(buf, (word)nbyte);
2982 # if defined(IRIX5) || defined(GC_LINUX_THREADS)
2983 /* Indirect system call may not always be easily available. */
2984 /* We could call _read, but that would interfere with the */
2985 /* libpthread interception of read. */
2986 /* On Linux, we have to be careful with the linuxthreads */
2987 /* read interception. */
2992 iov.iov_len = nbyte;
2993 result = readv(fd, &iov, 1);
2997 result = __read(fd, buf, nbyte);
2999 /* The two zero args at the end of this list are because one
3000 IA-64 syscall() implementation actually requires six args
3001 to be passed, even though they aren't always used. */
3002 result = syscall(SYS_read, fd, buf, nbyte, 0, 0);
3008 #endif /* !MSWIN32 && !MSWINCE && !GC_LINUX_THREADS */
3010 #if defined(GC_USE_LD_WRAP) && !defined(THREADS)
3011 /* We use the GNU ld call wrapping facility. */
3012 /* This requires that the linker be invoked with "--wrap read". */
3013 /* This can be done by passing -Wl,"--wrap read" to gcc. */
3014 /* I'm not sure that this actually wraps whatever version of read */
3015 /* is called by stdio. That code also mentions __read. */
3016 # include <unistd.h>
3017 ssize_t __wrap_read(int fd, void *buf, size_t nbyte)
3022 GC_unprotect_range(buf, (word)nbyte);
3023 result = __real_read(fd, buf, nbyte);
3028 /* We should probably also do this for __read, or whatever stdio */
3029 /* actually calls. */
3035 GC_bool GC_page_was_ever_dirty(h)
3041 /* Reset the n pages starting at h to "was never dirty" status. */
3043 void GC_is_fresh(h, n)
3049 # endif /* MPROTECT_VDB */
3054 * See DEFAULT_VDB for interface descriptions.
3058 * This implementaion assumes a Solaris 2.X like /proc pseudo-file-system
3059 * from which we can read page modified bits. This facility is far from
3060 * optimal (e.g. we would like to get the info for only some of the
3061 * address space), but it avoids intercepting system calls.
3065 #include <sys/types.h>
3066 #include <sys/signal.h>
3067 #include <sys/fault.h>
3068 #include <sys/syscall.h>
3069 #include <sys/procfs.h>
3070 #include <sys/stat.h>
3072 #define INITIAL_BUF_SZ 16384
3073 word GC_proc_buf_size = INITIAL_BUF_SZ;
3076 #ifdef GC_SOLARIS_THREADS
3077 /* We don't have exact sp values for threads. So we count on */
3078 /* occasionally declaring stack pages to be fresh. Thus we */
3079 /* need a real implementation of GC_is_fresh. We can't clear */
3080 /* entries in GC_written_pages, since that would declare all */
3081 /* pages with the given hash address to be fresh. */
3082 # define MAX_FRESH_PAGES 8*1024 /* Must be power of 2 */
3083 struct hblk ** GC_fresh_pages; /* A direct mapped cache. */
3084 /* Collisions are dropped. */
3086 # define FRESH_PAGE_SLOT(h) (divHBLKSZ((word)(h)) & (MAX_FRESH_PAGES-1))
3087 # define ADD_FRESH_PAGE(h) \
3088 GC_fresh_pages[FRESH_PAGE_SLOT(h)] = (h)
3089 # define PAGE_IS_FRESH(h) \
3090 (GC_fresh_pages[FRESH_PAGE_SLOT(h)] == (h) && (h) != 0)
3093 /* Add all pages in pht2 to pht1 */
3094 void GC_or_pages(pht1, pht2)
3095 page_hash_table pht1, pht2;
3099 for (i = 0; i < PHT_SIZE; i++) pht1[i] |= pht2[i];
3104 void GC_dirty_init()
3109 GC_dirty_maintained = TRUE;
3110 if (GC_words_allocd != 0 || GC_words_allocd_before_gc != 0) {
3113 for (i = 0; i < PHT_SIZE; i++) GC_written_pages[i] = (word)(-1);
3115 GC_printf1("Allocated words:%lu:all pages may have been written\n",
3117 (GC_words_allocd + GC_words_allocd_before_gc));
3120 sprintf(buf, "/proc/%d", getpid());
3121 fd = open(buf, O_RDONLY);
3123 ABORT("/proc open failed");
3125 GC_proc_fd = syscall(SYS_ioctl, fd, PIOCOPENPD, 0);
3127 syscall(SYS_fcntl, GC_proc_fd, F_SETFD, FD_CLOEXEC);
3128 if (GC_proc_fd < 0) {
3129 ABORT("/proc ioctl failed");
3131 GC_proc_buf = GC_scratch_alloc(GC_proc_buf_size);
3132 # ifdef GC_SOLARIS_THREADS
3133 GC_fresh_pages = (struct hblk **)
3134 GC_scratch_alloc(MAX_FRESH_PAGES * sizeof (struct hblk *));
3135 if (GC_fresh_pages == 0) {
3136 GC_err_printf0("No space for fresh pages\n");
3139 BZERO(GC_fresh_pages, MAX_FRESH_PAGES * sizeof (struct hblk *));
3143 /* Ignore write hints. They don't help us here. */
3145 void GC_remove_protection(h, nblocks, is_ptrfree)
3152 #ifdef GC_SOLARIS_THREADS
3153 # define READ(fd,buf,nbytes) syscall(SYS_read, fd, buf, nbytes)
3155 # define READ(fd,buf,nbytes) read(fd, buf, nbytes)
3158 void GC_read_dirty()
3160 unsigned long ps, np;
3163 struct prasmap * map;
3165 ptr_t current_addr, limit;
3169 BZERO(GC_grungy_pages, (sizeof GC_grungy_pages));
3172 if (READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
3174 GC_printf1("/proc read failed: GC_proc_buf_size = %lu\n",
3178 /* Retry with larger buffer. */
3179 word new_size = 2 * GC_proc_buf_size;
3180 char * new_buf = GC_scratch_alloc(new_size);
3183 GC_proc_buf = bufp = new_buf;
3184 GC_proc_buf_size = new_size;
3186 if (READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
3187 WARN("Insufficient space for /proc read\n", 0);
3189 memset(GC_grungy_pages, 0xff, sizeof (page_hash_table));
3190 memset(GC_written_pages, 0xff, sizeof(page_hash_table));
3191 # ifdef GC_SOLARIS_THREADS
3192 BZERO(GC_fresh_pages,
3193 MAX_FRESH_PAGES * sizeof (struct hblk *));
3199 /* Copy dirty bits into GC_grungy_pages */
3200 nmaps = ((struct prpageheader *)bufp) -> pr_nmap;
3201 /* printf( "nmaps = %d, PG_REFERENCED = %d, PG_MODIFIED = %d\n",
3202 nmaps, PG_REFERENCED, PG_MODIFIED); */
3203 bufp = bufp + sizeof(struct prpageheader);
3204 for (i = 0; i < nmaps; i++) {
3205 map = (struct prasmap *)bufp;
3206 vaddr = (ptr_t)(map -> pr_vaddr);
3207 ps = map -> pr_pagesize;
3208 np = map -> pr_npage;
3209 /* printf("vaddr = 0x%X, ps = 0x%X, np = 0x%X\n", vaddr, ps, np); */
3210 limit = vaddr + ps * np;
3211 bufp += sizeof (struct prasmap);
3212 for (current_addr = vaddr;
3213 current_addr < limit; current_addr += ps){
3214 if ((*bufp++) & PG_MODIFIED) {
3215 register struct hblk * h = (struct hblk *) current_addr;
3217 while ((ptr_t)h < current_addr + ps) {
3218 register word index = PHT_HASH(h);
3220 set_pht_entry_from_index(GC_grungy_pages, index);
3221 # ifdef GC_SOLARIS_THREADS
3223 register int slot = FRESH_PAGE_SLOT(h);
3225 if (GC_fresh_pages[slot] == h) {
3226 GC_fresh_pages[slot] = 0;
3234 bufp += sizeof(long) - 1;
3235 bufp = (char *)((unsigned long)bufp & ~(sizeof(long)-1));
3237 /* Update GC_written_pages. */
3238 GC_or_pages(GC_written_pages, GC_grungy_pages);
3239 # ifdef GC_SOLARIS_THREADS
3240 /* Make sure that old stacks are considered completely clean */
3241 /* unless written again. */
3242 GC_old_stacks_are_fresh();
3248 GC_bool GC_page_was_dirty(h)
3251 register word index = PHT_HASH(h);
3252 register GC_bool result;
3254 result = get_pht_entry_from_index(GC_grungy_pages, index);
3255 # ifdef GC_SOLARIS_THREADS
3256 if (result && PAGE_IS_FRESH(h)) result = FALSE;
3257 /* This happens only if page was declared fresh since */
3258 /* the read_dirty call, e.g. because it's in an unused */
3259 /* thread stack. It's OK to treat it as clean, in */
3260 /* that case. And it's consistent with */
3261 /* GC_page_was_ever_dirty. */
3266 GC_bool GC_page_was_ever_dirty(h)
3269 register word index = PHT_HASH(h);
3270 register GC_bool result;
3272 result = get_pht_entry_from_index(GC_written_pages, index);
3273 # ifdef GC_SOLARIS_THREADS
3274 if (result && PAGE_IS_FRESH(h)) result = FALSE;
3279 /* Caller holds allocation lock. */
3280 void GC_is_fresh(h, n)
3285 register word index;
3287 # ifdef GC_SOLARIS_THREADS
3290 if (GC_fresh_pages != 0) {
3291 for (i = 0; i < n; i++) {
3292 ADD_FRESH_PAGE(h + i);
3298 # endif /* PROC_VDB */
3303 # include "vd/PCR_VD.h"
3305 # define NPAGES (32*1024) /* 128 MB */
3307 PCR_VD_DB GC_grungy_bits[NPAGES];
3309 ptr_t GC_vd_base; /* Address corresponding to GC_grungy_bits[0] */
3310 /* HBLKSIZE aligned. */
3312 void GC_dirty_init()
3314 GC_dirty_maintained = TRUE;
3315 /* For the time being, we assume the heap generally grows up */
3316 GC_vd_base = GC_heap_sects[0].hs_start;
3317 if (GC_vd_base == 0) {
3318 ABORT("Bad initial heap segment");
3320 if (PCR_VD_Start(HBLKSIZE, GC_vd_base, NPAGES*HBLKSIZE)
3322 ABORT("dirty bit initialization failed");
3326 void GC_read_dirty()
3328 /* lazily enable dirty bits on newly added heap sects */
3330 static int onhs = 0;
3331 int nhs = GC_n_heap_sects;
3332 for( ; onhs < nhs; onhs++ ) {
3333 PCR_VD_WriteProtectEnable(
3334 GC_heap_sects[onhs].hs_start,
3335 GC_heap_sects[onhs].hs_bytes );
3340 if (PCR_VD_Clear(GC_vd_base, NPAGES*HBLKSIZE, GC_grungy_bits)
3342 ABORT("dirty bit read failed");
3346 GC_bool GC_page_was_dirty(h)
3349 if((ptr_t)h < GC_vd_base || (ptr_t)h >= GC_vd_base + NPAGES*HBLKSIZE) {
3352 return(GC_grungy_bits[h - (struct hblk *)GC_vd_base] & PCR_VD_DB_dirtyBit);
3356 void GC_remove_protection(h, nblocks, is_ptrfree)
3361 PCR_VD_WriteProtectDisable(h, nblocks*HBLKSIZE);
3362 PCR_VD_WriteProtectEnable(h, nblocks*HBLKSIZE);
3365 # endif /* PCR_VDB */
3367 #if defined(MPROTECT_VDB) && defined(DARWIN)
3368 /* The following sources were used as a *reference* for this exception handling
3370 1. Apple's mach/xnu documentation
3371 2. Timothy J. Wood's "Mach Exception Handlers 101" post to the
3372 omnigroup's macosx-dev list.
3373 www.omnigroup.com/mailman/archive/macosx-dev/2000-June/002030.html
3374 3. macosx-nat.c from Apple's GDB source code.
3377 /* The bug that caused all this trouble should now be fixed. This should
3378 eventually be removed if all goes well. */
3379 /* define BROKEN_EXCEPTION_HANDLING */
3381 #include <mach/mach.h>
3382 #include <mach/mach_error.h>
3383 #include <mach/thread_status.h>
3384 #include <mach/exception.h>
3385 #include <mach/task.h>
3386 #include <pthread.h>
3388 /* These are not defined in any header, although they are documented */
3389 extern boolean_t exc_server(mach_msg_header_t *,mach_msg_header_t *);
3390 extern kern_return_t exception_raise(
3391 mach_port_t,mach_port_t,mach_port_t,
3392 exception_type_t,exception_data_t,mach_msg_type_number_t);
3393 extern kern_return_t exception_raise_state(
3394 mach_port_t,mach_port_t,mach_port_t,
3395 exception_type_t,exception_data_t,mach_msg_type_number_t,
3396 thread_state_flavor_t*,thread_state_t,mach_msg_type_number_t,
3397 thread_state_t,mach_msg_type_number_t*);
3398 extern kern_return_t exception_raise_state_identity(
3399 mach_port_t,mach_port_t,mach_port_t,
3400 exception_type_t,exception_data_t,mach_msg_type_number_t,
3401 thread_state_flavor_t*,thread_state_t,mach_msg_type_number_t,
3402 thread_state_t,mach_msg_type_number_t*);
3405 #define MAX_EXCEPTION_PORTS 16
3408 mach_msg_type_number_t count;
3409 exception_mask_t masks[MAX_EXCEPTION_PORTS];
3410 exception_handler_t ports[MAX_EXCEPTION_PORTS];
3411 exception_behavior_t behaviors[MAX_EXCEPTION_PORTS];
3412 thread_state_flavor_t flavors[MAX_EXCEPTION_PORTS];
3416 mach_port_t exception;
3417 #if defined(THREADS)
3423 mach_msg_header_t head;
3427 GC_MP_NORMAL, GC_MP_DISCARDING, GC_MP_STOPPED
3428 } GC_mprotect_state_t;
3430 /* FIXME: 1 and 2 seem to be safe to use in the msgh_id field,
3431 but it isn't documented. Use the source and see if they
3436 /* These values are only used on the reply port */
3439 #if defined(THREADS)
3441 GC_mprotect_state_t GC_mprotect_state;
3443 /* The following should ONLY be called when the world is stopped */
3444 static void GC_mprotect_thread_notify(mach_msg_id_t id) {
3447 mach_msg_trailer_t trailer;
3449 mach_msg_return_t r;
3451 buf.msg.head.msgh_bits =
3452 MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND,0);
3453 buf.msg.head.msgh_size = sizeof(buf.msg);
3454 buf.msg.head.msgh_remote_port = GC_ports.exception;
3455 buf.msg.head.msgh_local_port = MACH_PORT_NULL;
3456 buf.msg.head.msgh_id = id;
3460 MACH_SEND_MSG|MACH_RCV_MSG|MACH_RCV_LARGE,
3464 MACH_MSG_TIMEOUT_NONE,
3466 if(r != MACH_MSG_SUCCESS)
3467 ABORT("mach_msg failed in GC_mprotect_thread_notify");
3468 if(buf.msg.head.msgh_id != ID_ACK)
3469 ABORT("invalid ack in GC_mprotect_thread_notify");
3472 /* Should only be called by the mprotect thread */
3473 static void GC_mprotect_thread_reply() {
3475 mach_msg_return_t r;
3477 msg.head.msgh_bits =
3478 MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND,0);
3479 msg.head.msgh_size = sizeof(msg);
3480 msg.head.msgh_remote_port = GC_ports.reply;
3481 msg.head.msgh_local_port = MACH_PORT_NULL;
3482 msg.head.msgh_id = ID_ACK;
3490 MACH_MSG_TIMEOUT_NONE,
3492 if(r != MACH_MSG_SUCCESS)
3493 ABORT("mach_msg failed in GC_mprotect_thread_reply");
3496 void GC_mprotect_stop() {
3497 GC_mprotect_thread_notify(ID_STOP);
3499 void GC_mprotect_resume() {
3500 GC_mprotect_thread_notify(ID_RESUME);
3503 #else /* !THREADS */
3504 /* The compiler should optimize away any GC_mprotect_state computations */
3505 #define GC_mprotect_state GC_MP_NORMAL
3508 static void *GC_mprotect_thread(void *arg) {
3509 mach_msg_return_t r;
3510 /* These two structures contain some private kernel data. We don't need to
3511 access any of it so we don't bother defining a proper struct. The
3512 correct definitions are in the xnu source code. */
3514 mach_msg_header_t head;
3518 mach_msg_header_t head;
3519 mach_msg_body_t msgh_body;
3525 GC_darwin_register_mach_handler_thread(mach_thread_self());
3530 MACH_RCV_MSG|MACH_RCV_LARGE|
3531 (GC_mprotect_state == GC_MP_DISCARDING ? MACH_RCV_TIMEOUT : 0),
3535 GC_mprotect_state == GC_MP_DISCARDING ? 0 : MACH_MSG_TIMEOUT_NONE,
3538 id = r == MACH_MSG_SUCCESS ? msg.head.msgh_id : -1;
3540 #if defined(THREADS)
3541 if(GC_mprotect_state == GC_MP_DISCARDING) {
3542 if(r == MACH_RCV_TIMED_OUT) {
3543 GC_mprotect_state = GC_MP_STOPPED;
3544 GC_mprotect_thread_reply();
3547 if(r == MACH_MSG_SUCCESS && (id == ID_STOP || id == ID_RESUME))
3548 ABORT("out of order mprotect thread request");
3552 if(r != MACH_MSG_SUCCESS) {
3553 GC_err_printf2("mach_msg failed with %d %s\n",
3554 (int)r,mach_error_string(r));
3555 ABORT("mach_msg failed");
3559 #if defined(THREADS)
3561 if(GC_mprotect_state != GC_MP_NORMAL)
3562 ABORT("Called mprotect_stop when state wasn't normal");
3563 GC_mprotect_state = GC_MP_DISCARDING;
3566 if(GC_mprotect_state != GC_MP_STOPPED)
3567 ABORT("Called mprotect_resume when state wasn't stopped");
3568 GC_mprotect_state = GC_MP_NORMAL;
3569 GC_mprotect_thread_reply();
3571 #endif /* THREADS */
3573 /* Handle the message (calls catch_exception_raise) */
3574 if(!exc_server(&msg.head,&reply.head))
3575 ABORT("exc_server failed");
3576 /* Send the reply */
3580 reply.head.msgh_size,
3583 MACH_MSG_TIMEOUT_NONE,
3585 if(r != MACH_MSG_SUCCESS) {
3586 /* This will fail if the thread dies, but the thread shouldn't
3588 #ifdef BROKEN_EXCEPTION_HANDLING
3590 "mach_msg failed with %d %s while sending exc reply\n",
3591 (int)r,mach_error_string(r));
3593 ABORT("mach_msg failed while sending exception reply");
3602 /* All this SIGBUS code shouldn't be necessary. All protection faults should
3603 be going throught the mach exception handler. However, it seems a SIGBUS is
3604 occasionally sent for some unknown reason. Even more odd, it seems to be
3605 meaningless and safe to ignore. */
3606 #ifdef BROKEN_EXCEPTION_HANDLING
3608 typedef void (* SIG_PF)();
3609 static SIG_PF GC_old_bus_handler;
3611 /* Updates to this aren't atomic, but the SIGBUSs seem pretty rare.
3612 Even if this doesn't get updated property, it isn't really a problem */
3613 static int GC_sigbus_count;
3615 static void GC_darwin_sigbus(int num,siginfo_t *sip,void *context) {
3616 if(num != SIGBUS) ABORT("Got a non-sigbus signal in the sigbus handler");
3618 /* Ugh... some seem safe to ignore, but too many in a row probably means
3619 trouble. GC_sigbus_count is reset for each mach exception that is
3621 if(GC_sigbus_count >= 8) {
3622 ABORT("Got more than 8 SIGBUSs in a row!");
3625 GC_err_printf0("GC: WARNING: Ignoring SIGBUS.\n");
3628 #endif /* BROKEN_EXCEPTION_HANDLING */
3630 void GC_dirty_init() {
3634 pthread_attr_t attr;
3635 exception_mask_t mask;
3638 GC_printf0("Inititalizing mach/darwin mprotect virtual dirty bit "
3639 "implementation\n");
3641 # ifdef BROKEN_EXCEPTION_HANDLING
3642 GC_err_printf0("GC: WARNING: Enabling workarounds for various darwin "
3643 "exception handling bugs.\n");
3645 GC_dirty_maintained = TRUE;
3646 if (GC_page_size % HBLKSIZE != 0) {
3647 GC_err_printf0("Page size not multiple of HBLKSIZE\n");
3648 ABORT("Page size not multiple of HBLKSIZE");
3651 GC_task_self = me = mach_task_self();
3653 r = mach_port_allocate(me,MACH_PORT_RIGHT_RECEIVE,&GC_ports.exception);
3654 if(r != KERN_SUCCESS) ABORT("mach_port_allocate failed (exception port)");
3656 r = mach_port_insert_right(me,GC_ports.exception,GC_ports.exception,
3657 MACH_MSG_TYPE_MAKE_SEND);
3658 if(r != KERN_SUCCESS)
3659 ABORT("mach_port_insert_right failed (exception port)");
3661 #if defined(THREADS)
3662 r = mach_port_allocate(me,MACH_PORT_RIGHT_RECEIVE,&GC_ports.reply);
3663 if(r != KERN_SUCCESS) ABORT("mach_port_allocate failed (reply port)");
3666 /* The exceptions we want to catch */
3667 mask = EXC_MASK_BAD_ACCESS;
3669 r = task_get_exception_ports(
3672 GC_old_exc_ports.masks,
3673 &GC_old_exc_ports.count,
3674 GC_old_exc_ports.ports,
3675 GC_old_exc_ports.behaviors,
3676 GC_old_exc_ports.flavors
3678 if(r != KERN_SUCCESS) ABORT("task_get_exception_ports failed");
3680 r = task_set_exception_ports(
3685 MACHINE_THREAD_STATE
3687 if(r != KERN_SUCCESS) ABORT("task_set_exception_ports failed");
3689 if(pthread_attr_init(&attr) != 0) ABORT("pthread_attr_init failed");
3690 if(pthread_attr_setdetachstate(&attr,PTHREAD_CREATE_DETACHED) != 0)
3691 ABORT("pthread_attr_setdetachedstate failed");
3693 # undef pthread_create
3694 /* This will call the real pthread function, not our wrapper */
3695 if(pthread_create(&thread,&attr,GC_mprotect_thread,NULL) != 0)
3696 ABORT("pthread_create failed");
3697 pthread_attr_destroy(&attr);
3699 /* Setup the sigbus handler for ignoring the meaningless SIGBUSs */
3700 #ifdef BROKEN_EXCEPTION_HANDLING
3702 struct sigaction sa, oldsa;
3703 sa.sa_handler = (SIG_PF)GC_darwin_sigbus;
3704 sigemptyset(&sa.sa_mask);
3705 sa.sa_flags = SA_RESTART|SA_SIGINFO;
3706 if(sigaction(SIGBUS,&sa,&oldsa) < 0) ABORT("sigaction");
3707 GC_old_bus_handler = (SIG_PF)oldsa.sa_handler;
3708 if (GC_old_bus_handler != SIG_DFL) {
3710 GC_err_printf0("Replaced other SIGBUS handler\n");
3714 #endif /* BROKEN_EXCEPTION_HANDLING */
3717 /* The source code for Apple's GDB was used as a reference for the exception
3718 forwarding code. This code is similar to be GDB code only because there is
3719 only one way to do it. */
3720 static kern_return_t GC_forward_exception(
3723 exception_type_t exception,
3724 exception_data_t data,
3725 mach_msg_type_number_t data_count
3730 exception_behavior_t behavior;
3731 thread_state_flavor_t flavor;
3733 thread_state_t thread_state;
3734 mach_msg_type_number_t thread_state_count = THREAD_STATE_MAX;
3736 for(i=0;i<GC_old_exc_ports.count;i++)
3737 if(GC_old_exc_ports.masks[i] & (1 << exception))
3739 if(i==GC_old_exc_ports.count) ABORT("No handler for exception!");
3741 port = GC_old_exc_ports.ports[i];
3742 behavior = GC_old_exc_ports.behaviors[i];
3743 flavor = GC_old_exc_ports.flavors[i];
3745 if(behavior != EXCEPTION_DEFAULT) {
3746 r = thread_get_state(thread,flavor,thread_state,&thread_state_count);
3747 if(r != KERN_SUCCESS)
3748 ABORT("thread_get_state failed in forward_exception");
3752 case EXCEPTION_DEFAULT:
3753 r = exception_raise(port,thread,task,exception,data,data_count);
3755 case EXCEPTION_STATE:
3756 r = exception_raise_state(port,thread,task,exception,data,
3757 data_count,&flavor,thread_state,thread_state_count,
3758 thread_state,&thread_state_count);
3760 case EXCEPTION_STATE_IDENTITY:
3761 r = exception_raise_state_identity(port,thread,task,exception,data,
3762 data_count,&flavor,thread_state,thread_state_count,
3763 thread_state,&thread_state_count);
3766 r = KERN_FAILURE; /* make gcc happy */
3767 ABORT("forward_exception: unknown behavior");
3771 if(behavior != EXCEPTION_DEFAULT) {
3772 r = thread_set_state(thread,flavor,thread_state,thread_state_count);
3773 if(r != KERN_SUCCESS)
3774 ABORT("thread_set_state failed in forward_exception");
3780 #define FWD() GC_forward_exception(thread,task,exception,code,code_count)
3782 /* This violates the namespace rules but there isn't anything that can be done
3783 about it. The exception handling stuff is hard coded to call this */
3785 catch_exception_raise(
3786 mach_port_t exception_port,mach_port_t thread,mach_port_t task,
3787 exception_type_t exception,exception_data_t code,
3788 mach_msg_type_number_t code_count
3794 # if defined(POWERPC)
3795 # if CPP_WORDSZ == 32
3796 thread_state_flavor_t flavor = PPC_EXCEPTION_STATE;
3797 mach_msg_type_number_t exc_state_count = PPC_EXCEPTION_STATE_COUNT;
3798 ppc_exception_state_t exc_state;
3800 thread_state_flavor_t flavor = PPC_EXCEPTION_STATE64;
3801 mach_msg_type_number_t exc_state_count = PPC_EXCEPTION_STATE64_COUNT;
3802 ppc_exception_state64_t exc_state;
3805 # error FIXME for non-ppc darwin
3809 if(exception != EXC_BAD_ACCESS || code[0] != KERN_PROTECTION_FAILURE) {
3810 #ifdef DEBUG_EXCEPTION_HANDLING
3811 /* We aren't interested, pass it on to the old handler */
3812 GC_printf3("Exception: 0x%x Code: 0x%x 0x%x in catch....\n",
3814 code_count > 0 ? code[0] : -1,
3815 code_count > 1 ? code[1] : -1);
3820 r = thread_get_state(thread,flavor,
3821 (natural_t*)&exc_state,&exc_state_count);
3822 if(r != KERN_SUCCESS) {
3823 /* The thread is supposed to be suspended while the exception handler
3824 is called. This shouldn't fail. */
3825 #ifdef BROKEN_EXCEPTION_HANDLING
3826 GC_err_printf0("thread_get_state failed in "
3827 "catch_exception_raise\n");
3828 return KERN_SUCCESS;
3830 ABORT("thread_get_state failed in catch_exception_raise");
3834 /* This is the address that caused the fault */
3835 addr = (char*) exc_state.dar;
3837 if((HDR(addr)) == 0) {
3838 /* Ugh... just like the SIGBUS problem above, it seems we get a bogus
3839 KERN_PROTECTION_FAILURE every once and a while. We wait till we get
3840 a bunch in a row before doing anything about it. If a "real" fault
3841 ever occurres it'll just keep faulting over and over and we'll hit
3842 the limit pretty quickly. */
3843 #ifdef BROKEN_EXCEPTION_HANDLING
3844 static char *last_fault;
3845 static int last_fault_count;
3847 if(addr != last_fault) {
3849 last_fault_count = 0;
3851 if(++last_fault_count < 32) {
3852 if(last_fault_count == 1)
3854 "GC: WARNING: Ignoring KERN_PROTECTION_FAILURE at %p\n",
3856 return KERN_SUCCESS;
3859 GC_err_printf1("Unexpected KERN_PROTECTION_FAILURE at %p\n",addr);
3860 /* Can't pass it along to the signal handler because that is
3861 ignoring SIGBUS signals. We also shouldn't call ABORT here as
3862 signals don't always work too well from the exception handler. */
3863 GC_err_printf0("Aborting\n");
3865 #else /* BROKEN_EXCEPTION_HANDLING */
3866 /* Pass it along to the next exception handler
3867 (which should call SIGBUS/SIGSEGV) */
3869 #endif /* !BROKEN_EXCEPTION_HANDLING */
3872 #ifdef BROKEN_EXCEPTION_HANDLING
3873 /* Reset the number of consecutive SIGBUSs */
3874 GC_sigbus_count = 0;
3877 if(GC_mprotect_state == GC_MP_NORMAL) { /* common case */
3878 h = (struct hblk*)((word)addr & ~(GC_page_size-1));
3879 UNPROTECT(h, GC_page_size);
3880 for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
3881 register int index = PHT_HASH(h+i);
3882 async_set_pht_entry_from_index(GC_dirty_pages, index);
3884 } else if(GC_mprotect_state == GC_MP_DISCARDING) {
3885 /* Lie to the thread for now. No sense UNPROTECT()ing the memory
3886 when we're just going to PROTECT() it again later. The thread
3887 will just fault again once it resumes */
3889 /* Shouldn't happen, i don't think */
3890 GC_printf0("KERN_PROTECTION_FAILURE while world is stopped\n");
3893 return KERN_SUCCESS;
3897 /* These should never be called, but just in case... */
3898 kern_return_t catch_exception_raise_state(mach_port_name_t exception_port,
3899 int exception, exception_data_t code, mach_msg_type_number_t codeCnt,
3900 int flavor, thread_state_t old_state, int old_stateCnt,
3901 thread_state_t new_state, int new_stateCnt)
3903 ABORT("catch_exception_raise_state");
3904 return(KERN_INVALID_ARGUMENT);
3906 kern_return_t catch_exception_raise_state_identity(
3907 mach_port_name_t exception_port, mach_port_t thread, mach_port_t task,
3908 int exception, exception_data_t code, mach_msg_type_number_t codeCnt,
3909 int flavor, thread_state_t old_state, int old_stateCnt,
3910 thread_state_t new_state, int new_stateCnt)
3912 ABORT("catch_exception_raise_state_identity");
3913 return(KERN_INVALID_ARGUMENT);
3917 #endif /* DARWIN && MPROTECT_VDB */
3919 # ifndef HAVE_INCREMENTAL_PROTECTION_NEEDS
3920 int GC_incremental_protection_needs()
3922 return GC_PROTECTS_NONE;
3924 # endif /* !HAVE_INCREMENTAL_PROTECTION_NEEDS */
3927 * Call stack save code for debugging.
3928 * Should probably be in mach_dep.c, but that requires reorganization.
3931 /* I suspect the following works for most X86 *nix variants, so */
3932 /* long as the frame pointer is explicitly stored. In the case of gcc, */
3933 /* compiler flags (e.g. -fomit-frame-pointer) determine whether it is. */
3934 #if defined(I386) && defined(LINUX) && defined(SAVE_CALL_CHAIN)
3935 # include <features.h>
3938 struct frame *fr_savfp;
3940 long fr_arg[NARGS]; /* All the arguments go here. */
3946 # include <features.h>
3951 struct frame *fr_savfp;
3960 # if defined(SUNOS4)
3961 # include <machine/frame.h>
3963 # if defined (DRSNX)
3964 # include <sys/sparc/frame.h>
3966 # if defined(OPENBSD)
3969 # if defined(FREEBSD) || defined(NETBSD)
3970 # include <machine/frame.h>
3972 # include <sys/frame.h>
3979 --> We only know how to to get the first 6 arguments
3983 #ifdef NEED_CALLINFO
3984 /* Fill in the pc and argument information for up to NFRAMES of my */
3985 /* callers. Ignore my frame and my callers frame. */
3988 # include <unistd.h>
3991 #endif /* NEED_CALLINFO */
3993 #if defined(GC_HAVE_BUILTIN_BACKTRACE)
3994 # include <execinfo.h>
3997 #ifdef SAVE_CALL_CHAIN
3999 #if NARGS == 0 && NFRAMES % 2 == 0 /* No padding */ \
4000 && defined(GC_HAVE_BUILTIN_BACKTRACE)
4002 #ifdef REDIRECT_MALLOC
4003 /* Deal with possible malloc calls in backtrace by omitting */
4004 /* the infinitely recursing backtrace. */
4006 __thread /* If your compiler doesn't understand this */
4007 /* you could use something like pthread_getspecific. */
4009 GC_in_save_callers = FALSE;
4012 void GC_save_callers (info)
4013 struct callinfo info[NFRAMES];
4015 void * tmp_info[NFRAMES + 1];
4017 # define IGNORE_FRAMES 1
4019 /* We retrieve NFRAMES+1 pc values, but discard the first, since it */
4020 /* points to our own frame. */
4021 # ifdef REDIRECT_MALLOC
4022 if (GC_in_save_callers) {
4023 info[0].ci_pc = (word)(&GC_save_callers);
4024 for (i = 1; i < NFRAMES; ++i) info[i].ci_pc = 0;
4027 GC_in_save_callers = TRUE;
4029 GC_ASSERT(sizeof(struct callinfo) == sizeof(void *));
4030 npcs = backtrace((void **)tmp_info, NFRAMES + IGNORE_FRAMES);
4031 BCOPY(tmp_info+IGNORE_FRAMES, info, (npcs - IGNORE_FRAMES) * sizeof(void *));
4032 for (i = npcs - IGNORE_FRAMES; i < NFRAMES; ++i) info[i].ci_pc = 0;
4033 # ifdef REDIRECT_MALLOC
4034 GC_in_save_callers = FALSE;
4038 #else /* No builtin backtrace; do it ourselves */
4040 #if (defined(OPENBSD) || defined(NETBSD) || defined(FREEBSD)) && defined(SPARC)
4041 # define FR_SAVFP fr_fp
4042 # define FR_SAVPC fr_pc
4044 # define FR_SAVFP fr_savfp
4045 # define FR_SAVPC fr_savpc
4048 #if defined(SPARC) && (defined(__arch64__) || defined(__sparcv9))
4054 void GC_save_callers (info)
4055 struct callinfo info[NFRAMES];
4057 struct frame *frame;
4061 /* We assume this is turned on only with gcc as the compiler. */
4062 asm("movl %%ebp,%0" : "=r"(frame));
4065 frame = (struct frame *) GC_save_regs_in_stack ();
4066 fp = (struct frame *)((long) frame -> FR_SAVFP + BIAS);
4069 for (; (!(fp HOTTER_THAN frame) && !(GC_stackbottom HOTTER_THAN (ptr_t)fp)
4070 && (nframes < NFRAMES));
4071 fp = (struct frame *)((long) fp -> FR_SAVFP + BIAS), nframes++) {
4074 info[nframes].ci_pc = fp->FR_SAVPC;
4076 for (i = 0; i < NARGS; i++) {
4077 info[nframes].ci_arg[i] = ~(fp->fr_arg[i]);
4079 # endif /* NARGS > 0 */
4081 if (nframes < NFRAMES) info[nframes].ci_pc = 0;
4084 #endif /* No builtin backtrace */
4086 #endif /* SAVE_CALL_CHAIN */
4088 #ifdef NEED_CALLINFO
4090 /* Print info to stderr. We do NOT hold the allocation lock */
4091 void GC_print_callers (info)
4092 struct callinfo info[NFRAMES];
4095 static int reentry_count = 0;
4096 GC_bool stop = FALSE;
4098 /* FIXME: This should probably use a different lock, so that we */
4099 /* become callable with or without the allocation lock. */
4105 GC_err_printf0("\tCaller at allocation:\n");
4107 GC_err_printf0("\tCall chain at allocation:\n");
4109 for (i = 0; i < NFRAMES && !stop ; i++) {
4110 if (info[i].ci_pc == 0) break;
4115 GC_err_printf0("\t\targs: ");
4116 for (j = 0; j < NARGS; j++) {
4117 if (j != 0) GC_err_printf0(", ");
4118 GC_err_printf2("%d (0x%X)", ~(info[i].ci_arg[j]),
4119 ~(info[i].ci_arg[j]));
4121 GC_err_printf0("\n");
4124 if (reentry_count > 1) {
4125 /* We were called during an allocation during */
4126 /* a previous GC_print_callers call; punt. */
4127 GC_err_printf1("\t\t##PC##= 0x%lx\n", info[i].ci_pc);
4134 # if defined(GC_HAVE_BUILTIN_BACKTRACE) \
4135 && !defined(GC_BACKTRACE_SYMBOLS_BROKEN)
4137 backtrace_symbols((void **)(&(info[i].ci_pc)), 1);
4138 char *name = sym_name[0];
4142 sprintf(buf, "##PC##= 0x%lx", info[i].ci_pc);
4144 # if defined(LINUX) && !defined(SMALL_CONFIG)
4145 /* Try for a line number. */
4148 static char exe_name[EXE_SZ];
4150 char cmd_buf[CMD_SZ];
4151 # define RESULT_SZ 200
4152 static char result_buf[RESULT_SZ];
4155 # define PRELOAD_SZ 200
4156 char preload_buf[PRELOAD_SZ];
4157 static GC_bool found_exe_name = FALSE;
4158 static GC_bool will_fail = FALSE;
4160 /* Try to get it via a hairy and expensive scheme. */
4161 /* First we get the name of the executable: */
4162 if (will_fail) goto out;
4163 if (!found_exe_name) {
4164 ret_code = readlink("/proc/self/exe", exe_name, EXE_SZ);
4165 if (ret_code < 0 || ret_code >= EXE_SZ
4166 || exe_name[0] != '/') {
4167 will_fail = TRUE; /* Dont try again. */
4170 exe_name[ret_code] = '\0';
4171 found_exe_name = TRUE;
4173 /* Then we use popen to start addr2line -e <exe> <addr> */
4174 /* There are faster ways to do this, but hopefully this */
4175 /* isn't time critical. */
4176 sprintf(cmd_buf, "/usr/bin/addr2line -f -e %s 0x%lx", exe_name,
4177 (unsigned long)info[i].ci_pc);
4178 old_preload = getenv ("LD_PRELOAD");
4179 if (0 != old_preload) {
4180 if (strlen (old_preload) >= PRELOAD_SZ) {
4184 strcpy (preload_buf, old_preload);
4185 unsetenv ("LD_PRELOAD");
4187 pipe = popen(cmd_buf, "r");
4188 if (0 != old_preload
4189 && 0 != setenv ("LD_PRELOAD", preload_buf, 0)) {
4190 WARN("Failed to reset LD_PRELOAD\n", 0);
4193 || (result_len = fread(result_buf, 1, RESULT_SZ - 1, pipe))
4195 if (pipe != NULL) pclose(pipe);
4199 if (result_buf[result_len - 1] == '\n') --result_len;
4200 result_buf[result_len] = 0;
4201 if (result_buf[0] == '?'
4202 || result_buf[result_len-2] == ':'
4203 && result_buf[result_len-1] == '0') {
4207 /* Get rid of embedded newline, if any. Test for "main" */
4209 char * nl = strchr(result_buf, '\n');
4210 if (nl != NULL && nl < result_buf + result_len) {
4213 if (strncmp(result_buf, "main", nl - result_buf) == 0) {
4217 if (result_len < RESULT_SZ - 25) {
4218 /* Add in hex address */
4219 sprintf(result_buf + result_len, " [0x%lx]",
4220 (unsigned long)info[i].ci_pc);
4227 GC_err_printf1("\t\t%s\n", name);
4228 # if defined(GC_HAVE_BUILTIN_BACKTRACE) \
4229 && !defined(GC_BACKTRACE_SYMBOLS_BROKEN)
4230 free(sym_name); /* May call GC_free; that's OK */
4239 #endif /* NEED_CALLINFO */
4243 #if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG)
4245 /* Dump /proc/self/maps to GC_stderr, to enable looking up names for
4246 addresses in FIND_LEAK output. */
4248 static word dump_maps(char *maps)
4250 GC_err_write(maps, strlen(maps));
4254 void GC_print_address_map()
4256 GC_err_printf0("---------- Begin address map ----------\n");
4257 GC_apply_to_maps(dump_maps);
4258 GC_err_printf0("---------- End address map ----------\n");